20139993520 has 40 divisors (see below), whose sum is σ = 46837310256. Its totient is φ = 8053963008.

The previous prime is 20139993443. The next prime is 20139993553. The reversal of 20139993520 is 2539993102.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (43) coincides with the sum of the digits of its distinct prime factors.

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, 309774 + ... + 369106.

Almost surely, 2^20139993520 is an apocalyptic number.

20139993520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20139993520 is an abundant number, since it is smaller than the sum of its proper divisors (26697316736).

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

20139993520 is a wasteful number, since it uses less digits than its factorization.

20139993520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63589 (or 63583 counting only the distinct ones).

The product of its (nonzero) digits is 131220, while the sum is 43.

The spelling of 20139993520 in words is "twenty billion, one hundred thirty-nine million, nine hundred ninety-three thousand, five hundred twenty".