49 = 7 squared

50 - the number of ways there are to leave your lover.

51 - Area 51, a U.S. military-controlled land in southern Nevada, apparently containing a secret aircraft testing facility

52 - weeks in a year

53-
In 1953 , in England we had the coronation of Queen Elzabeth 2nd and Sir Edmund Hillary climbed Mt. Everest.

54, In japanese, pronounced "go juu yon"

55 - Emerald wedding anniversary

56. Both 7 x 8 and 8 x 7.

(my sister still doesn't know that)

57 - Heinz 57 Varieties! (soup)

58 - The minimum wind speed needed to issue a Severe Thunderstorm Warning.

59 -th day in a year is Feb. 28th

59 - One day on planet Mercury lasts about 59 Earth days.

60 - Domitius Afer, a Roman orator died in the year 60.

61 -- The code for international direct dial phone calls to Australia

62 - the age at which Ed Sullivan introduced the Beatles to America in 1964 !

63 - The number of chromosomes found in the offspring of a donkey and a horse

64 - The number of squares on a chess board.

65 - The protein in egg whites coagulate at 65 degrees C (150 degrees F).

66 is the 6th double number

67 -th day of the year is March 9th or March 8th in a leap year

68 -- a happy number

for more on happy numbers

69 - which looks the same upside down.

70 - "The days of our years are threescore years and ten".

71-
71 is the algebraic degree of Conway's constant, a remarkable number arising in the study of look-and-say sequences.

It is the 20th prime number. The next is 73, with which it composes a twin prime. It is also a permutable prime with 17. If we add up the primes less than 71 (2 through 67), we get 568, which is divisible by 71, 8 times. 71 is the largest supersingular prime. Also, 712 = 7! + 1, making it part of the last known pair of Brown numbers, as (71, 7). It is an Eisenstein prime with no imaginary part and real part of the form 3n − 1. Since 9! + 1 is divisible by 71 but 71 is not one more than a multiple of 9, 71 is a Pillai prime.

71 is a centered heptagonal number.

72 - LXXII in roman numerals