79111991 has 8 divisors (see below), whose sum is σ = 95172480. Its totient is φ = 64241208.

The previous prime is 79111961. The next prime is 79111993. The reversal of 79111991 is 19911197.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 79111991 - 2²⁶ = 12003127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79111993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 297281 + ... + 297546.

It is an arithmetic number, because the mean of its divisors is an integer number (11896560).

Almost surely, 2^79111991 is an apocalyptic number.

79111991 is a deficient number, since it is larger than the sum of its proper divisors (16060489).

79111991 is a wasteful number, since it uses less digits than its factorization.

79111991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594853.

The product of its digits is 5103, while the sum is 38.

The square root of 79111991 is about 8894.4921721254. The cubic root of 79111991 is about 429.2867045670.

The spelling of 79111991 in words is "seventy-nine million, one hundred eleven thousand, nine hundred ninety-one".