31368402561 has 4 divisors (see below), whose sum is σ = 41824536752. Its totient is φ = 20912268372.

The previous prime is 31368402539. The next prime is 31368402623. The reversal of 31368402561 is 16520486313.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 31368402561 - 2⁹ = 31368402049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31368402511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5228067091 + ... + 5228067096.

It is an arithmetic number, because the mean of its divisors is an integer number (10456134188).

Almost surely, 2^31368402561 is an apocalyptic number.

It is an amenable number.

31368402561 is a deficient number, since it is larger than the sum of its proper divisors (10456134191).

31368402561 is a wasteful number, since it uses less digits than its factorization.

31368402561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10456134190.

The product of its (nonzero) digits is 103680, while the sum is 39.

Adding to 31368402561 its reverse (16520486313), we get a palindrome (47888888874).

The spelling of 31368402561 in words is "thirty-one billion, three hundred sixty-eight million, four hundred two thousand, five hundred sixty-one".