20501957508 has 48 divisors (see below), whose sum is σ = 51083880960. Its totient is φ = 6385478400.

The previous prime is 20501957491. The next prime is 20501957513. The reversal of 20501957508 is 80575910502.

It is a self number, because there is not a number n which added to its sum of digits gives 20501957508.

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, 939433 + ... + 961008.

It is an arithmetic number, because the mean of its divisors is an integer number (1064247520).

Almost surely, 2^20501957508 is an apocalyptic number.

It is an amenable number.

20501957508 is an abundant number, since it is smaller than the sum of its proper divisors (30581923452).

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

20501957508 is a wasteful number, since it uses less digits than its factorization.

20501957508 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1900508 (or 1900506 counting only the distinct ones).

The product of its (nonzero) digits is 126000, while the sum is 42.

The spelling of 20501957508 in words is "twenty billion, five hundred one million, nine hundred fifty-seven thousand, five hundred eight".