51531797 has 2 divisors, whose sum is σ = 51531798. Its totient is φ = 51531796.

The previous prime is 51531769. The next prime is 51531833. The reversal of 51531797 is 79713515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33477796 + 18054001 = 5786^2 + 4249^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-51531797 is a prime.

It is a super-2 number, since 2×51531797² = 5311052204098418, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51531797.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51531737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25765898 + 25765899.

It is an arithmetic number, because the mean of its divisors is an integer number (25765899).

Almost surely, 2^51531797 is an apocalyptic number.

It is an amenable number.

51531797 is a deficient number, since it is larger than the sum of its proper divisors (1).

51531797 is an equidigital number, since it uses as much as digits as its factorization.

51531797 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 33075, while the sum is 38.

The square root of 51531797 is about 7178.5651073178. The cubic root of 51531797 is about 372.1274975350.

The spelling of 51531797 in words is "fifty-one million, five hundred thirty-one thousand, seven hundred ninety-seven".