31506625613 has 2 divisors, whose sum is σ = 31506625614. Its totient is φ = 31506625612.

The previous prime is 31506625573. The next prime is 31506625621. The reversal of 31506625613 is 31652660513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30109884484 + 1396741129 = 173522^2 + 37373^2 .

It is a cyclic number.

It is not a de Polignac number, because 31506625613 - 2²² = 31502431309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31506621613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15753312806 + 15753312807.

It is an arithmetic number, because the mean of its divisors is an integer number (15753312807).

Almost surely, 2^31506625613 is an apocalyptic number.

It is an amenable number.

31506625613 is a deficient number, since it is larger than the sum of its proper divisors (1).

31506625613 is an equidigital number, since it uses as much as digits as its factorization.

31506625613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 97200, while the sum is 38.

The spelling of 31506625613 in words is "thirty-one billion, five hundred six million, six hundred twenty-five thousand, six hundred thirteen".