18189980 has 24 divisors (see below), whose sum is σ = 38419920. Its totient is φ = 7233920.

The previous prime is 18189979. The next prime is 18189991. The reversal of 18189980 is 8998181.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1040 + ... + 6120.

It is an arithmetic number, because the mean of its divisors is an integer number (1600830).

Almost surely, 2^18189980 is an apocalyptic number.

18189980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18189980 is an abundant number, since it is smaller than the sum of its proper divisors (20229940).

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

18189980 is a wasteful number, since it uses less digits than its factorization.

18189980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5269 (or 5267 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 18189980 is about 4264.9712777462. The cubic root of 18189980 is about 262.9929301689.

The spelling of 18189980 in words is "eighteen million, one hundred eighty-nine thousand, nine hundred eighty".