79999631 has 4 divisors (see below), whose sum is σ = 81509112. Its totient is φ = 78490152.

The previous prime is 79999627. The next prime is 79999657. The reversal of 79999631 is 13699997.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 79999631 - 2² = 79999627 is a prime.

It is a super-2 number, since 2×79999631² = 12799881920272322, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (53), and also a Moran number because the ratio is a prime number: 1509427 = 79999631 / (7 + 9 + 9 + 9 + 9 + 6 + 3 + 1).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (79999531) 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, 754661 + ... + 754766.

It is an arithmetic number, because the mean of its divisors is an integer number (20377278).

Almost surely, 2^79999631 is an apocalyptic number.

79999631 is a deficient number, since it is larger than the sum of its proper divisors (1509481).

79999631 is a wasteful number, since it uses less digits than its factorization.

79999631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1509480.

The product of its digits is 826686, while the sum is 53.

The square root of 79999631 is about 8944.2512822483. The cubic root of 79999631 is about 430.8862755167.

The spelling of 79999631 in words is "seventy-nine million, nine hundred ninety-nine thousand, six hundred thirty-one".