991371312 has 50 divisors (see below), whose sum is σ = 2869319948. Its totient is φ = 330456672.

The previous prime is 991371281. The next prime is 991371343. The reversal of 991371312 is 213173199.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (991371281) and next prime (991371343).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 381178 + ... + 383769.

Almost surely, 2^991371312 is an apocalyptic number.

It is an amenable number.

991371312 is an abundant number, since it is smaller than the sum of its proper divisors (1877948636).

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

991371312 is a wasteful number, since it uses less digits than its factorization.

991371312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 764967 (or 764952 counting only the distinct ones).

The product of its digits is 10206, while the sum is 36.

The square root of 991371312 is about 31486.0494822707. The cubic root of 991371312 is about 997.1154580850.

It can be divided in two parts, 9913 and 71312, that added together give a square (81225 = 285²).

The spelling of 991371312 in words is "nine hundred ninety-one million, three hundred seventy-one thousand, three hundred twelve".