18538380 has 72 divisors (see below), whose sum is σ = 64270752. Its totient is φ = 4237056.

The previous prime is 18538367. The next prime is 18538427. The reversal of 18538380 is 8383581.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6097 + ... + 8616.

Almost surely, 2^18538380 is an apocalyptic number.

18538380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18538380 is an abundant number, since it is smaller than the sum of its proper divisors (45732372).

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

18538380 is a wasteful number, since it uses less digits than its factorization.

18538380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14735 (or 14730 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 18538380 is about 4305.6219062988. The cubic root of 18538380 is about 264.6613926101.

The spelling of 18538380 in words is "eighteen million, five hundred thirty-eight thousand, three hundred eighty".