Ingrid Bergman was a Swedish actress who starred in a variety of European and American films. She won three Academy Awards, two Emmy Awards, four Golden Globe Awards and a Tony Award for Best Actress. She is best remembered for her roles in Casablanca (1942) and Notorious (1946).
August 29, 2015 marked Bergman’s 100th birthday as well as the 33rd anniversary of her death. She was born August 29, 1915 (also known as 29 August 1915) in Stockholm, Sweden and died on August 29, 1982 (also known as 29 August 1982) in London, England. In her honor and to celebrate her centennial birthday, I constructed the following five numerical brainteasers:

1. If numbers are assigned to the letters of the alphabet (both Swedish and English, in this case) with A being 1, B is 2, C is 3, etc., the numbers assigned to the letters of "Ingrid" and "Bergman" add up to 61 and 60, the sum of which yield 121. Interestingly, the square of the sum of the digits of the day number of Bergman’s birthday (29), also add up to 121.


2. Bergman died on 29-8-1982 in which the leftmost and rightmost three digits contain the same three digits: 2, 8 and 9. Bergman’s 13th birthday, expressed as 29-8-1928, had the same property. In addition, if her 13th birthday is expressed in the month-day-year date format as 8-29-1928, it is a palindrome.

3. The digits of Bergman’s birth year, 1915, can be added up to equal 16. The reverse of this is 61, which coincided with the sum of the numbers assigned to the letters of Bergman’s first name "Ingrid." Also, half of 16 yields 8, the month number of Bergman’s birthdate.

4. If the reverse of Bergman’s birth year 1915 is 5191, it can be split as 51 and 91, adding up to 142, the reverse of which is also 241: Bergman was born on the 241st day of 1915.

5. Casablanca had its world premiere in 1942. Interestingly, the digits of 1942 add up to 16, and 19 plus 42 (which side by side make up 1942) yield 61 ("Ingrid"). Also, 2491 (which is the reverse of 1942) equals 47 x 53, where primes 47 and 53 add up to 100.

By Aziz S. Inan professor of electrical engineering at Donald P. Shiley School of Engineering, University of Portland, Oregon, who watched and enjoyed Bergman’s movies while growing up.