991551360 has 64 divisors (see below), whose sum is σ = 3160576080. Its totient is φ = 264413184.

The previous prime is 991551313. The next prime is 991551371. The reversal of 991551360 is 63155199.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 256297 + ... + 260136.

Almost surely, 2^991551360 is an apocalyptic number.

It is an amenable number.

991551360 is an abundant number, since it is smaller than the sum of its proper divisors (2169024720).

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

991551360 is a wasteful number, since it uses less digits than its factorization.

991551360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 516455 (or 516443 counting only the distinct ones).

The product of its (nonzero) digits is 36450, while the sum is 39.

The square root of 991551360 is about 31488.9085234785. The cubic root of 991551360 is about 997.1758181722.

The spelling of 991551360 in words is "nine hundred ninety-one million, five hundred fifty-one thousand, three hundred sixty".