31599979779 has 4 divisors (see below), whose sum is σ = 42133306376. Its totient is φ = 21066653184.

The previous prime is 31599979777. The next prime is 31599979783. The reversal of 31599979779 is 97797999513.

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

It is not a de Polignac number, because 31599979779 - 2¹ = 31599979777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 31599979779.

It is not an unprimeable number, because it can be changed into a prime (31599979771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5266663294 + ... + 5266663299.

It is an arithmetic number, because the mean of its divisors is an integer number (10533326594).

Almost surely, 2^31599979779 is an apocalyptic number.

31599979779 is a deficient number, since it is larger than the sum of its proper divisors (10533326597).

31599979779 is a wasteful number, since it uses less digits than its factorization.

31599979779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10533326596.

The product of its digits is 303807105, while the sum is 75.

The spelling of 31599979779 in words is "thirty-one billion, five hundred ninety-nine million, nine hundred seventy-nine thousand, seven hundred seventy-nine".