999915972 has 48 divisors (see below), whose sum is σ = 2614043712. Its totient is φ = 294814080.

The previous prime is 999915971. The next prime is 999915991. The reversal of 999915972 is 279519999.

It is not an unprimeable number, because it can be changed into a prime (999915971) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97483 + ... + 107250.

It is an arithmetic number, because the mean of its divisors is an integer number (54459244).

Almost surely, 2^999915972 is an apocalyptic number.

It is an amenable number.

999915972 is an abundant number, since it is smaller than the sum of its proper divisors (1614127740).

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

999915972 is a wasteful number, since it uses less digits than its factorization.

999915972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 204788 (or 204786 counting only the distinct ones).

The product of its digits is 4133430, while the sum is 60.

The square root of 999915972 is about 31621.4479744366. The cubic root of 999915972 is about 999.9719898821.

The spelling of 999915972 in words is "nine hundred ninety-nine million, nine hundred fifteen thousand, nine hundred seventy-two".