31210421257 has 2 divisors, whose sum is σ = 31210421258. Its totient is φ = 31210421256.

The previous prime is 31210421239. The next prime is 31210421303. The reversal of 31210421257 is 75212401213.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21181600521 + 10028820736 = 145539^2 + 100144^2 .

It is a cyclic number.

It is not a de Polignac number, because 31210421257 - 2⁷ = 31210421129 is a prime.

It is not a weakly prime, because it can be changed into another prime (31210461257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15605210628 + 15605210629.

It is an arithmetic number, because the mean of its divisors is an integer number (15605210629).

Almost surely, 2^31210421257 is an apocalyptic number.

It is an amenable number.

31210421257 is a deficient number, since it is larger than the sum of its proper divisors (1).

31210421257 is an equidigital number, since it uses as much as digits as its factorization.

31210421257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3360, while the sum is 28.

The spelling of 31210421257 in words is "thirty-one billion, two hundred ten million, four hundred twenty-one thousand, two hundred fifty-seven".