79181997 has 4 divisors (see below), whose sum is σ = 105576000. Its totient is φ = 52787996.

The previous prime is 79181989. The next prime is 79182011. The reversal of 79181997 is 79918197.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 79181997 - 2³ = 79181989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79181497) 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 3 ways as a sum of consecutive naturals, for example, 13196997 + ... + 13197002.

It is an arithmetic number, because the mean of its divisors is an integer number (26394000).

Almost surely, 2^79181997 is an apocalyptic number.

It is an amenable number.

79181997 is a deficient number, since it is larger than the sum of its proper divisors (26394003).

79181997 is a wasteful number, since it uses less digits than its factorization.

79181997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26394002.

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

The square root of 79181997 is about 8898.4266586852. The cubic root of 79181997 is about 429.4132921404.

The spelling of 79181997 in words is "seventy-nine million, one hundred eighty-one thousand, nine hundred ninety-seven".