79991905 has 16 divisors (see below), whose sum is σ = 111565440. Its totient is φ = 53920512.

The previous prime is 79991897. The next prime is 79991917. The reversal of 79991905 is 50919997.

It is a cyclic number.

It is not a de Polignac number, because 79991905 - 2³ = 79991897 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17304 + ... + 21433.

It is an arithmetic number, because the mean of its divisors is an integer number (6972840).

Almost surely, 2^79991905 is an apocalyptic number.

It is an amenable number.

79991905 is a deficient number, since it is larger than the sum of its proper divisors (31573535).

79991905 is a wasteful number, since it uses less digits than its factorization.

79991905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38808.

The product of its (nonzero) digits is 229635, while the sum is 49.

The square root of 79991905 is about 8943.8193742942. The cubic root of 79991905 is about 430.8724040588.

The spelling of 79991905 in words is "seventy-nine million, nine hundred ninety-one thousand, nine hundred five".