31605503257 has 2 divisors, whose sum is σ = 31605503258. Its totient is φ = 31605503256.

The previous prime is 31605503201. The next prime is 31605503269. The reversal of 31605503257 is 75230550613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 28823890176 + 2781613081 = 169776^2 + 52741^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31605503257 is a prime.

It is a super-2 number, since 2×31605503257² (a number of 22 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (31605503297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15802751628 + 15802751629.

It is an arithmetic number, because the mean of its divisors is an integer number (15802751629).

Almost surely, 2^31605503257 is an apocalyptic number.

It is an amenable number.

31605503257 is a deficient number, since it is larger than the sum of its proper divisors (1).

31605503257 is an equidigital number, since it uses as much as digits as its factorization.

31605503257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 94500, while the sum is 37.

The spelling of 31605503257 in words is "thirty-one billion, six hundred five million, five hundred three thousand, two hundred fifty-seven".