31513315609 has 2 divisors, whose sum is σ = 31513315610. Its totient is φ = 31513315608.

The previous prime is 31513315549. The next prime is 31513315643. The reversal of 31513315609 is 90651331513.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30921464025 + 591851584 = 175845^2 + 24328^2 .

It is a cyclic number.

It is not a de Polignac number, because 31513315609 - 2²⁷ = 31379097881 is a prime.

It is not a weakly prime, because it can be changed into another prime (31513315649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15756657804 + 15756657805.

It is an arithmetic number, because the mean of its divisors is an integer number (15756657805).

Almost surely, 2^31513315609 is an apocalyptic number.

It is an amenable number.

31513315609 is a deficient number, since it is larger than the sum of its proper divisors (1).

31513315609 is an equidigital number, since it uses as much as digits as its factorization.

31513315609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36450, while the sum is 37.

The spelling of 31513315609 in words is "thirty-one billion, five hundred thirteen million, three hundred fifteen thousand, six hundred nine".