991764280 has 128 divisors (see below), whose sum is σ = 2598926400. Its totient is φ = 337416192.

The previous prime is 991764269. The next prime is 991764311. The reversal of 991764280 is 82467199.

It is a self number, because there is not a number n which added to its sum of digits gives 991764280.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 364204 + ... + 366916.

Almost surely, 2^991764280 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 991764280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1299463200).

991764280 is an abundant number, since it is smaller than the sum of its proper divisors (1607162120).

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

991764280 is a wasteful number, since it uses less digits than its factorization.

991764280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2793 (or 2789 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 46.

The square root of 991764280 is about 31492.2892149809. The cubic root of 991764280 is about 997.2471889851.

The spelling of 991764280 in words is "nine hundred ninety-one million, seven hundred sixty-four thousand, two hundred eighty".