991957595264 has 16 divisors (see below), whose sum is σ = 1976165522070. Its totient is φ = 495978797568.

The previous prime is 991957595149. The next prime is 991957595339. The reversal of 991957595264 is 462595759199.

991957595264 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 532327833664 + 459629761600 = 729608^2 + 677960^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3874834229 + ... + 3874834484.

Almost surely, 2^991957595264 is an apocalyptic number.

It is an amenable number.

991957595264 is a deficient number, since it is larger than the sum of its proper divisors (984207926806).

991957595264 is an equidigital number, since it uses as much as digits as its factorization.

991957595264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7749668727 (or 7749668715 counting only the distinct ones).

The product of its digits is 275562000, while the sum is 71.

The spelling of 991957595264 in words is "nine hundred ninety-one billion, nine hundred fifty-seven million, five hundred ninety-five thousand, two hundred sixty-four".