18871312 has 20 divisors (see below), whose sum is σ = 37743616. Its totient is φ = 9131040.

The previous prime is 18871301. The next prime is 18871331. The reversal of 18871312 is 21317881.

It is a happy number.

18871312 is an admirable number.

It is a super-2 number, since 2×18871312² = 712252833202688, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18528 + ... + 19519.

Almost surely, 2^18871312 is an apocalyptic number.

It is an amenable number.

18871312 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

18871312 is a wasteful number, since it uses less digits than its factorization.

18871312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38086 (or 38080 counting only the distinct ones).

The product of its digits is 2688, while the sum is 31.

The square root of 18871312 is about 4344.1123374057. The cubic root of 18871312 is about 266.2363587830.

The spelling of 18871312 in words is "eighteen million, eight hundred seventy-one thousand, three hundred twelve".