18718540 has 24 divisors (see below), whose sum is σ = 40052880. Its totient is φ = 7345728.

The previous prime is 18718523. The next prime is 18718541. The reversal of 18718540 is 4581781.

It is a junction number, because it is equal to n+sod(n) for n = 18718496 and 18718505.

It is not an unprimeable number, because it can be changed into a prime (18718541) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7770 + ... + 9889.

It is an arithmetic number, because the mean of its divisors is an integer number (1668870).

Almost surely, 2^18718540 is an apocalyptic number.

18718540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18718540 is an abundant number, since it is smaller than the sum of its proper divisors (21334340).

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

18718540 is a wasteful number, since it uses less digits than its factorization.

18718540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17721 (or 17719 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 34.

The square root of 18718540 is about 4326.4928059573. The cubic root of 18718540 is about 265.5159758345.

The spelling of 18718540 in words is "eighteen million, seven hundred eighteen thousand, five hundred forty".