20979972986 has 32 divisors (see below), whose sum is σ = 38858486400. Its totient is φ = 8462505408.

The previous prime is 20979972977. The next prime is 20979973039. The reversal of 20979972986 is 68927997902.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 887840 + ... + 911163.

It is an arithmetic number, because the mean of its divisors is an integer number (1214327700).

Almost surely, 2^20979972986 is an apocalyptic number.

20979972986 is a deficient number, since it is larger than the sum of its proper divisors (17878513414).

20979972986 is a wasteful number, since it uses less digits than its factorization.

20979972986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1799043 (or 1799029 counting only the distinct ones).

The product of its (nonzero) digits is 61725888, while the sum is 68.

The spelling of 20979972986 in words is "twenty billion, nine hundred seventy-nine million, nine hundred seventy-two thousand, nine hundred eighty-six".