18399620 has 24 divisors (see below), whose sum is σ = 38742144. Its totient is φ = 7340256.

The previous prime is 18399587. The next prime is 18399637. The reversal of 18399620 is 2699381.

It is a super-2 number, since 2×18399620² = 677092032288800, which contains 22 as substring.

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, 8267 + ... + 10253.

It is an arithmetic number, because the mean of its divisors is an integer number (1614256).

Almost surely, 2^18399620 is an apocalyptic number.

18399620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18399620 is an abundant number, since it is smaller than the sum of its proper divisors (20342524).

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

18399620 is a wasteful number, since it uses less digits than its factorization.

18399620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2459 (or 2457 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 18399620 is about 4289.4778236984. The cubic root of 18399620 is about 263.9994069469. Note that the first 3 decimals are identical.

The spelling of 18399620 in words is "eighteen million, three hundred ninety-nine thousand, six hundred twenty".