18718520 has 16 divisors (see below), whose sum is σ = 42116760. Its totient is φ = 7487392.

The previous prime is 18718519. The next prime is 18718523. The reversal of 18718520 is 2581781.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18718523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 233942 + ... + 234021.

Almost surely, 2^18718520 is an apocalyptic number.

18718520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18718520 is an abundant number, since it is smaller than the sum of its proper divisors (23398240).

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

18718520 is a wasteful number, since it uses less digits than its factorization.

18718520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 467974 (or 467970 counting only the distinct ones).

The product of its (nonzero) digits is 4480, while the sum is 32.

The square root of 18718520 is about 4326.4904946157. The cubic root of 18718520 is about 265.5158812701.

The spelling of 18718520 in words is "eighteen million, seven hundred eighteen thousand, five hundred twenty".