31815730661 has 16 divisors (see below), whose sum is σ = 37390429440. Its totient is φ = 26689581120.

The previous prime is 31815730643. The next prime is 31815730691. The reversal of 31815730661 is 16603751813.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-31815730661 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31815730691) 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 15 ways as a sum of consecutive naturals, for example, 410351 + ... + 481683.

It is an arithmetic number, because the mean of its divisors is an integer number (2336901840).

Almost surely, 2^31815730661 is an apocalyptic number.

It is an amenable number.

31815730661 is a deficient number, since it is larger than the sum of its proper divisors (5574698779).

31815730661 is a wasteful number, since it uses less digits than its factorization.

31815730661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74476.

The product of its (nonzero) digits is 90720, while the sum is 41.

The spelling of 31815730661 in words is "thirty-one billion, eight hundred fifteen million, seven hundred thirty thousand, six hundred sixty-one".