811917968 has 20 divisors (see below), whose sum is σ = 1575449388. Its totient is φ = 405350400.

The previous prime is 811917961. The next prime is 811917979. The reversal of 811917968 is 869719118.

It can be written as a sum of positive squares in 2 ways, for example, as 275161744 + 536756224 = 16588^2 + 23168^2 .

It is a super-2 number, since 2×811917968² = 1318421573522498048, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (811917961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26933 + ... + 48468.

Almost surely, 2^811917968 is an apocalyptic number.

It is an amenable number.

811917968 is a deficient number, since it is larger than the sum of its proper divisors (763531420).

811917968 is a wasteful number, since it uses less digits than its factorization.

811917968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 76082 (or 76076 counting only the distinct ones).

The product of its digits is 217728, while the sum is 50.

The square root of 811917968 is about 28494.1742817721. The cubic root of 811917968 is about 932.9049215242.

The spelling of 811917968 in words is "eight hundred eleven million, nine hundred seventeen thousand, nine hundred sixty-eight".