Annelies Marie "Anne" Frank, a Dutch-Jewish diarist, was born June 12, 1929, in Frankfurt. Her story is well known. Her family moved to Amsterdam to avoid complications caused by the Nazi Party. At 13, Anne received a red and white autograph book that she used as a dairy.

She began writing in mid-June 1942. A month later, her family went into hiding in a secret apartment behind her father's business in German-occupied Amsterdam. After 25 months in hiding, they were discovered and sent to the Auschwitz-Birkenau extermination and concentration camp. Anne and her sister were sent to Bergen-Belsen, a concentration camp in Northern Germany, where they died of typhus.

Otto Frank was the only member of the family to survive the Holocaust. He was liberated from Auschwitz by Soviet troops in January 1945. He eventually published Anne's writings, and they became the book everyone knows today: "The Dairy of a Young Girl."

Frank's diary represents a testament to the indestructible characteristics of humanity and a symbol of resilience to racism and discrimination. June 12 would have been her 90th birthday. I prepared these numerical birthday curiosities in her memory:

• Frank's 90th birthday occurs this week on 12 June (12/6). Interestingly, 12 plus 6 equals 18, 12 times 6 is 72, and 18 plus 72 results in 90.

• Furthermore, the sum of the squares of 12 and 6 equals twice 90.

• Moreover, the product of the digits of 1945, the year Frank died, equals twice 90 too.

• Also, twice the rightmost two digits of 1945, namely 45, equals 90.

• Additionally, Frank died at age 15 and 15 multiplied by the sum of its digits, namely 6, equals 90 too.

• Three times the sum of the digits of Frank's birthday, 12/6/1929, namely 30, also equals 90.

• The product of the digits of Frank's birthday 12/6/1929 equals 1944, the year she and her family got arrested.

• The sum of the cubes of 12 and 6, the day and month numbers of Frank's birthdate, also yields 1944.

• Also, 6 times the reverse of 12, namely 21, yields back 126, that is, Frank's birthdate, 12 June (12/6).

• The prime multipliers of 126 add up to 2 + 3 + 3 + 7 = 15, the age Frank died.

• Frank's 89th birthday in 2018 expressed as 12/6/18 was special since 12 plus 6 equals 18.

• Further, Frank's birth name, Annelies Marie Frank, contains 18 letters.

• If Frank's birth year 1929 is split in the middle as 19 and 29, 19 and 29 are the 8th and 10th prime numbers and 8 plus 10 equals 18 too.

• Also, 18 interpreted as 1/8 or 1 August is the last day Frank made an entry in her diary in 1944.

• If Frank's 90th birthday expressed as 12/6/2019 is split as 126 and 2019, the sum of the prime factors of the reverse of 126, namely 621, equals 3 + 23 = 26 and the sum of the prime factors of 2019, namely 3 and 673, equals 26 square.

• Frank's 90th birthday expressed as 12/6/19 is the 163rd day of 2019 and interestingly, 163 is the 38th prime number and the reverse of 163, namely 361, is 19 x 19 and 19 plus 19 yields 38.

• Additionally, the sum of the prime factors of the reverse of 2019, namely 9102, equals 2 + 3 + 37 + 41 = 83 and note that 83 is the reverse of 38.

• Frank's 91st birthday in 2020 will also be special too because the reverse of 2020, namely 202, equals the total number of days left in each year after her birthday. Also, 91 equals 7 times 13, 7 plus 13 equals 20, and 20 is each half of 2020.

• Frank's 92nd birthday in 2021 expressed in short as 12/6/21 will be a palindrome day. Further, if her birth year 1929 is split as 19 and 29, the sum of the squares of these two numbers equals 1202 and note that 1202 is the reverse of 2021. Also, 92 is the middle two digits of 1929.

• Frank's 93rd birthday in 2022 will be interesting since the sum and the difference of the digits of 93 equal 12 and 6 respectively and 12 and 6 put side by side yields 12/6, Frank's birthdate. Additionally, the sum of the prime factors of 93, namely 3 and 31, equals 34 and 34 equals the sum of the letter numbers of Anne when letters A to Z are assigned numbers 1 to 26. Also, 2022 divided by the sum of its digits, namely 6, equals 337 and 337 is the 68th prime number and 68 is twice 34.

• Lastly, the sum of the letter numbers of Anne Frank equals 84 and the reverse of 84, namely 48, interpreted as 4 August (4/8) is the day she was arrested in 1944.

*Aziz Inan is chair and professor teaching in the electrical engineering program of the Donald P. Shiley School of Engineering at University of Portland. He can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..*