811993857 has 8 divisors (see below), whose sum is σ = 1082832576. Its totient is φ = 541242192.

The previous prime is 811993841. The next prime is 811993859. The reversal of 811993857 is 758399118.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 811993857 - 2⁴ = 811993841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (811993859) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4548 + ... + 40554.

It is an arithmetic number, because the mean of its divisors is an integer number (135354072).

Almost surely, 2^811993857 is an apocalyptic number.

It is an amenable number.

811993857 is a deficient number, since it is larger than the sum of its proper divisors (270838719).

811993857 is a wasteful number, since it uses less digits than its factorization.

811993857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43527.

The product of its digits is 544320, while the sum is 51.

The square root of 811993857 is about 28495.5059088271. The cubic root of 811993857 is about 932.9339864539.

The spelling of 811993857 in words is "eight hundred eleven million, nine hundred ninety-three thousand, eight hundred fifty-seven".