15999964 has 12 divisors (see below), whose sum is σ = 28027944. Its totient is φ = 7991984.

The previous prime is 15999961. The next prime is 15999983. The reversal of 15999964 is 46999951.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15999961) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6987 + ... + 8989.

It is an arithmetic number, because the mean of its divisors is an integer number (2335662).

Almost surely, 2^15999964 is an apocalyptic number.

It is an amenable number.

15999964 is a deficient number, since it is larger than the sum of its proper divisors (12027980).

15999964 is a wasteful number, since it uses less digits than its factorization.

15999964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4004 (or 4002 counting only the distinct ones).

The product of its digits is 787320, while the sum is 52.

The square root of 15999964 is about 3999.9954999975. The cubic root of 15999964 is about 251.9840209907.

The spelling of 15999964 in words is "fifteen million, nine hundred ninety-nine thousand, nine hundred sixty-four".