991011984 has 40 divisors (see below), whose sum is σ = 2622561312. Its totient is φ = 322279680.

The previous prime is 991011953. The next prime is 991012007. The reversal of 991011984 is 489110199.

It is a happy 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, 249814 + ... + 253749.

Almost surely, 2^991011984 is an apocalyptic number.

It is an amenable number.

991011984 is an abundant number, since it is smaller than the sum of its proper divisors (1631549328).

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

991011984 is a wasteful number, since it uses less digits than its factorization.

991011984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503615 (or 503609 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 42.

The square root of 991011984 is about 31480.3428189720. The cubic root of 991011984 is about 996.9949735279.

The spelling of 991011984 in words is "nine hundred ninety-one million, eleven thousand, nine hundred eighty-four".