7991664 has 40 divisors (see below), whose sum is σ = 20748672. Its totient is φ = 2650560.

The previous prime is 7991657. The next prime is 7991701. The reversal of 7991664 is 4661997.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15637 + ... + 16139.

Almost surely, 2^7991664 is an apocalyptic number.

It is an amenable number.

7991664 is an abundant number, since it is smaller than the sum of its proper divisors (12757008).

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

7991664 is a wasteful number, since it uses less digits than its factorization.

7991664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 845 (or 839 counting only the distinct ones).

The product of its digits is 81648, while the sum is 42.

The square root of 7991664 is about 2826.9531301385. The cubic root of 7991664 is about 199.9305091913.

The spelling of 7991664 in words is "seven million, nine hundred ninety-one thousand, six hundred sixty-four".