31309857923 has 2 divisors, whose sum is σ = 31309857924. Its totient is φ = 31309857922.

The previous prime is 31309857913. The next prime is 31309857941. The reversal of 31309857923 is 32975890313.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31309857923 - 2²² = 31305663619 is a prime.

It is not a weakly prime, because it can be changed into another prime (31309857913) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15654928961 + 15654928962.

It is an arithmetic number, because the mean of its divisors is an integer number (15654928962).

Almost surely, 2^31309857923 is an apocalyptic number.

31309857923 is a deficient number, since it is larger than the sum of its proper divisors (1).

31309857923 is an equidigital number, since it uses as much as digits as its factorization.

31309857923 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1224720, while the sum is 50.

The spelling of 31309857923 in words is "thirty-one billion, three hundred nine million, eight hundred fifty-seven thousand, nine hundred twenty-three".