991924 has 24 divisors (see below), whose sum is σ = 1823360. Its totient is φ = 471744.

The previous prime is 991909. The next prime is 991927. The reversal of 991924 is 429199.

991924 = T₁₂₇ + T₁₂₈ + ... + T₁₉₉.

991924 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 991924.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (991927) 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, 12517 + ... + 12595.

2⁹⁹¹⁹²⁴ is an apocalyptic number.

It is an amenable number.

991924 is a deficient number, since it is larger than the sum of its proper divisors (831436).

991924 is a wasteful number, since it uses less digits than its factorization.

991924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199 (or 197 counting only the distinct ones).

The product of its digits is 5832, while the sum is 34.

The square root of 991924 is about 995.9538141902. The cubic root of 991924 is about 99.7300720446.

The spelling of 991924 in words is "nine hundred ninety-one thousand, nine hundred twenty-four".