79400857 has 4 divisors (see below), whose sum is σ = 79442020. Its totient is φ = 79359696.

The previous prime is 79400851. The next prime is 79400873. The reversal of 79400857 is 75800497.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75800497 = 83 ⋅913259.

It can be written as a sum of positive squares in 2 ways, for example, as 77951241 + 1449616 = 8829^2 + 1204^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-79400857 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (79400851) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17538 + ... + 21595.

It is an arithmetic number, because the mean of its divisors is an integer number (19860505).

Almost surely, 2^79400857 is an apocalyptic number.

It is an amenable number.

79400857 is a deficient number, since it is larger than the sum of its proper divisors (41163).

79400857 is a wasteful number, since it uses less digits than its factorization.

79400857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41162.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 79400857 is about 8910.7158522758. The cubic root of 79400857 is about 429.8085627020.

The spelling of 79400857 in words is "seventy-nine million, four hundred thousand, eight hundred fifty-seven".