18871320 has 64 divisors (see below), whose sum is σ = 60973920. Its totient is φ = 4644864.

The previous prime is 18871301. The next prime is 18871331. The reversal of 18871320 is 2317881.

It is a happy number.

It is a super-2 number, since 2×18871320² = 712253437084800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4489 + ... + 7608.

Almost surely, 2^18871320 is an apocalyptic number.

18871320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18871320 is an abundant number, since it is smaller than the sum of its proper divisors (42102600).

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

18871320 is a wasteful number, since it uses less digits than its factorization.

18871320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12124 (or 12120 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 30.

The square root of 18871320 is about 4344.1132581921. The cubic root of 18871320 is about 266.2363964043.

It can be divided in two parts, 18871 and 320, that added together give a palindrome (19191).

The spelling of 18871320 in words is "eighteen million, eight hundred seventy-one thousand, three hundred twenty".