991984023 has 32 divisors (see below), whose sum is σ = 1514923200. Its totient is φ = 641063808.

The previous prime is 991984003. The next prime is 991984027. The reversal of 991984023 is 320489199.

It is not a de Polignac number, because 991984023 - 2⁵ = 991983991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 991984023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991984027) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 291013 + ... + 294401.

It is an arithmetic number, because the mean of its divisors is an integer number (47341350).

Almost surely, 2^991984023 is an apocalyptic number.

991984023 is a deficient number, since it is larger than the sum of its proper divisors (522939177).

991984023 is a wasteful number, since it uses less digits than its factorization.

991984023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3728 (or 3722 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 991984023 is about 31495.7778598973. Note that the first 3 decimals coincide. The cubic root of 991984023 is about 997.3208361580.

The spelling of 991984023 in words is "nine hundred ninety-one million, nine hundred eighty-four thousand, twenty-three".