79891791 has 32 divisors (see below), whose sum is σ = 124236288. Its totient is φ = 44728320.

The previous prime is 79891783. The next prime is 79891793. The reversal of 79891791 is 19719897.

It is not a de Polignac number, because 79891791 - 2³ = 79891783 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79891793) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 310735 + ... + 310991.

It is an arithmetic number, because the mean of its divisors is an integer number (3882384).

Almost surely, 2^79891791 is an apocalyptic number.

79891791 is a deficient number, since it is larger than the sum of its proper divisors (44344497).

79891791 is a wasteful number, since it uses less digits than its factorization.

79891791 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 511.

The product of its digits is 285768, while the sum is 51.

The square root of 79891791 is about 8938.2207961093. The cubic root of 79891791 is about 430.6925759950.

The spelling of 79891791 in words is "seventy-nine million, eight hundred ninety-one thousand, seven hundred ninety-one".