79820931 has 4 divisors (see below), whose sum is σ = 106427912. Its totient is φ = 53213952.

The previous prime is 79820929. The next prime is 79820987. The reversal of 79820931 is 13902897.

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

It is not a de Polignac number, because 79820931 - 2¹ = 79820929 is a prime.

It is a super-4 number, since 4×79820931⁴ (a number of 33 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 79820931.

It is not an unprimeable number, because it can be changed into a prime (79820131) 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, 13303486 + ... + 13303491.

It is an arithmetic number, because the mean of its divisors is an integer number (26606978).

Almost surely, 2^79820931 is an apocalyptic number.

79820931 is a deficient number, since it is larger than the sum of its proper divisors (26606981).

79820931 is a wasteful number, since it uses less digits than its factorization.

79820931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26606980.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 79820931 is about 8934.2560406561. The cubic root of 79820931 is about 430.5652041132.

The spelling of 79820931 in words is "seventy-nine million, eight hundred twenty thousand, nine hundred thirty-one".