991931016 has 16 divisors (see below), whose sum is σ = 2479827600. Its totient is φ = 330643664.

The previous prime is 991930997. The next prime is 991931029. The reversal of 991931016 is 610139199.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20665206 + ... + 20665253.

It is an arithmetic number, because the mean of its divisors is an integer number (154989225).

Almost surely, 2^991931016 is an apocalyptic number.

It is an amenable number.

991931016 is an abundant number, since it is smaller than the sum of its proper divisors (1487896584).

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

991931016 is a wasteful number, since it uses less digits than its factorization.

991931016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41330468 (or 41330464 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 39.

The square root of 991931016 is about 31494.9363549127. The cubic root of 991931016 is about 997.3030717835.

The spelling of 991931016 in words is "nine hundred ninety-one million, nine hundred thirty-one thousand, sixteen".