999972501608538 has 32 divisors (see below), whose sum is σ = 2222162189409600. Its totient is φ = 333324005994288.

The previous prime is 999972501608513. The next prime is 999972501608569. The reversal of 999972501608538 is 835806105279999.

999972501608538 is a `hidden beast` number, since 9 + 9 + 9 + 9 + 72 + 5 + 0 + 1 + 6 + 0 + 8 + 538 = 666.

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, 172059420 + ... + 177776232.

It is an arithmetic number, because the mean of its divisors is an integer number (69442568419050).

Almost surely, 2^{999972501608538} is an apocalyptic number.

999972501608538 is an abundant number, since it is smaller than the sum of its proper divisors (1222189687801062).

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

999972501608538 is a wasteful number, since it uses less digits than its factorization.

999972501608538 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8956043 (or 8956037 counting only the distinct ones).

The product of its (nonzero) digits is 2645395200, while the sum is 81.

The spelling of 999972501608538 in words is "nine hundred ninety-nine trillion, nine hundred seventy-two billion, five hundred one million, six hundred eight thousand, five hundred thirty-eight".