991424984 has 32 divisors (see below), whose sum is σ = 2031618240. Its totient is φ = 449824800.

The previous prime is 991424971. The next prime is 991424999. The reversal of 991424984 is 489424199.

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, 39539 + ... + 59549.

It is an arithmetic number, because the mean of its divisors is an integer number (63488070).

Almost surely, 2^991424984 is an apocalyptic number.

It is an amenable number.

991424984 is an abundant number, since it is smaller than the sum of its proper divisors (1040193256).

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

991424984 is a wasteful number, since it uses less digits than its factorization.

991424984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20591 (or 20587 counting only the distinct ones).

The product of its digits is 746496, while the sum is 50.

The square root of 991424984 is about 31486.9017847104. The cubic root of 991424984 is about 997.1334520880.

The spelling of 991424984 in words is "nine hundred ninety-one million, four hundred twenty-four thousand, nine hundred eighty-four".