20997878536 has 32 divisors (see below), whose sum is σ = 39624552000. Its totient is φ = 10431432256.

The previous prime is 20997878527. The next prime is 20997878563. The reversal of 20997878536 is 63587879902.

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, 1883250 + ... + 1894366.

It is an arithmetic number, because the mean of its divisors is an integer number (1238267250).

Almost surely, 2^20997878536 is an apocalyptic number.

It is an amenable number.

20997878536 is a deficient number, since it is larger than the sum of its proper divisors (18626673464).

20997878536 is a wasteful number, since it uses less digits than its factorization.

20997878536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12621 (or 12617 counting only the distinct ones).

The product of its (nonzero) digits is 45722880, while the sum is 64.

The spelling of 20997878536 in words is "twenty billion, nine hundred ninety-seven million, eight hundred seventy-eight thousand, five hundred thirty-six".