31811894806 has 4 divisors (see below), whose sum is σ = 47717842212. Its totient is φ = 15905947402.

The previous prime is 31811894791. The next prime is 31811894819. The reversal of 31811894806 is 60849811813.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×31811894806² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 31811894806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7952973700 + ... + 7952973703.

It is an arithmetic number, because the mean of its divisors is an integer number (11929460553).

Almost surely, 2^31811894806 is an apocalyptic number.

31811894806 is a deficient number, since it is larger than the sum of its proper divisors (15905947406).

31811894806 is a wasteful number, since it uses less digits than its factorization.

31811894806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15905947405.

The product of its (nonzero) digits is 331776, while the sum is 49.

The spelling of 31811894806 in words is "thirty-one billion, eight hundred eleven million, eight hundred ninety-four thousand, eight hundred six".