20979790624 has 48 divisors (see below), whose sum is σ = 46015051320. Its totient is φ = 9349079040.

The previous prime is 20979790619. The next prime is 20979790631. The reversal of 20979790624 is 42609797902.

It can be written as a sum of positive squares in 4 ways, for example, as 8341534224 + 12638256400 = 91332^2 + 112420^2 .

It is a super-2 number, since 2×20979790624² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 857457 + ... + 881584.

Almost surely, 2^20979790624 is an apocalyptic number.

It is an amenable number.

20979790624 is an abundant number, since it is smaller than the sum of its proper divisors (25035260696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20979790624 is a wasteful number, since it uses less digits than its factorization.

20979790624 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1739093 (or 1739085 counting only the distinct ones).

The product of its (nonzero) digits is 3429216, while the sum is 55.

The spelling of 20979790624 in words is "twenty billion, nine hundred seventy-nine million, seven hundred ninety thousand, six hundred twenty-four".