18871199 has 12 divisors (see below), whose sum is σ = 20590440. Its totient is φ = 17246880.

The previous prime is 18871183. The next prime is 18871211. The reversal of 18871199 is 99117881.

It is not a de Polignac number, because 18871199 - 2⁴ = 18871183 is a prime.

It is a super-2 number, since 2×18871199² = 712244303395202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18871499) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15389 + ... + 16569.

It is an arithmetic number, because the mean of its divisors is an integer number (1715870).

Almost surely, 2^18871199 is an apocalyptic number.

18871199 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

18871199 is a deficient number, since it is larger than the sum of its proper divisors (1719241).

18871199 is a wasteful number, since it uses less digits than its factorization.

18871199 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1258 (or 1229 counting only the distinct ones).

The product of its digits is 36288, while the sum is 44.

The square root of 18871199 is about 4344.0993312769. The cubic root of 18871199 is about 266.2358273808.

The spelling of 18871199 in words is "eighteen million, eight hundred seventy-one thousand, one hundred ninety-nine".