991873983 has 8 divisors (see below), whose sum is σ = 1322693248. Its totient is φ = 661152024.

The previous prime is 991873973. The next prime is 991873999. The reversal of 991873983 is 389378199.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 991873983 - 2⁵ = 991873951 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991873903) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4260 + ... + 44742.

It is an arithmetic number, because the mean of its divisors is an integer number (165336656).

Almost surely, 2^991873983 is an apocalyptic number.

991873983 is a deficient number, since it is larger than the sum of its proper divisors (330819265).

991873983 is a wasteful number, since it uses less digits than its factorization.

991873983 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48653.

The product of its digits is 2939328, while the sum is 57.

The square root of 991873983 is about 31494.0309106345. The cubic root of 991873983 is about 997.2839574582.

The spelling of 991873983 in words is "nine hundred ninety-one million, eight hundred seventy-three thousand, nine hundred eighty-three".