691 was the MAA (Mathematical Association of America) number of the day on 19 February 2013.
MathBabbler Number Analyst (MBNA) output: ========================================= 691 is a natural, whole, integer 691 is odd 691 proper divisors are: 1, 691 is deficient (sum of divisors is 1) 691 is unhappy 691 is a Squarefree Number 691 is not a Harshad number 691 is prime ...Truman Gerald prime with 661 ...OEIS:002145 (4n+3; n=164) 691 is the sum of 13 consecutive primes 691 = 29 + 31 + 37 + 41 + 43 + 47 + 53 + 59 + 61 + 67 + 71 + 73 + 79 691 in octal is 01263 691 in hexadecimal is 0x2b3 691 in binary is 1010110011 (is evil) 691 nearest square numbers: -15...38 (676...729 [27]) sqrt(691) = 26.2869 ln(691) = 6.53814 log(691) = 2.83948 691 reciprocal is .00144717800289435600578871201157 691! is 6.32012e+1663 691 is 219.952 Pi years 691 is 34 score and 11 years 691 written as a Roman numeral is DCXCI 691 = 346^2 - 345^2 and 346 + 345 = 691The MAA reported that
691is the "only prime number that is a square when turned upside down (169) and another square when reversed (196).The MBNA reported that
691is the sum of 13 consecutive primes and the MAA reported that it is the "smallest prime that can be written as the sum of thirteen consecutive primes."
Creator: Gerald Thurman
[gthurman@gmail.com]
Created: 19 February 2013
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