79911891 has 48 divisors (see below), whose sum is σ = 126896640. Its totient is φ = 48288960.

The previous prime is 79911877. The next prime is 79911919. The reversal of 79911891 is 19811997.

It is not a de Polignac number, because 79911891 - 2⁷ = 79911763 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79911851) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 490176 + ... + 490338.

It is an arithmetic number, because the mean of its divisors is an integer number (2643680).

Almost surely, 2^79911891 is an apocalyptic number.

79911891 is a deficient number, since it is larger than the sum of its proper divisors (46984749).

79911891 is a wasteful number, since it uses less digits than its factorization.

79911891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 296 (or 293 counting only the distinct ones).

The product of its digits is 40824, while the sum is 45.

The square root of 79911891 is about 8939.3451102416. The cubic root of 79911891 is about 430.7286923251.

The spelling of 79911891 in words is "seventy-nine million, nine hundred eleven thousand, eight hundred ninety-one".