21179131616 has 24 divisors (see below), whose sum is σ = 41704110504. Its totient is φ = 10587611520.

The previous prime is 21179131601. The next prime is 21179131651. The reversal of 21179131616 is 61613197112.

It is a self number, because there is not a number n which added to its sum of digits gives 21179131616.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 123626 + ... + 240086.

It is an arithmetic number, because the mean of its divisors is an integer number (1737671271).

Almost surely, 2^21179131616 is an apocalyptic number.

It is an amenable number.

21179131616 is a deficient number, since it is larger than the sum of its proper divisors (20524978888).

21179131616 is a wasteful number, since it uses less digits than its factorization.

21179131616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 122154 (or 122146 counting only the distinct ones).

The product of its digits is 13608, while the sum is 38.

The spelling of 21179131616 in words is "twenty-one billion, one hundred seventy-nine million, one hundred thirty-one thousand, six hundred sixteen".