18401868 has 18 divisors (see below), whose sum is σ = 46515924. Its totient is φ = 6133944.

The previous prime is 18401857. The next prime is 18401927. The reversal of 18401868 is 86810481.

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 511163 = 18401868 / (1 + 8 + 4 + 0 + 1 + 8 + 6 + 8).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 255546 + ... + 255617.

It is an arithmetic number, because the mean of its divisors is an integer number (2584218).

Almost surely, 2^18401868 is an apocalyptic number.

18401868 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

18401868 is an abundant number, since it is smaller than the sum of its proper divisors (28114056).

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

18401868 is a wasteful number, since it uses less digits than its factorization.

18401868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 511173 (or 511168 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 36.

The square root of 18401868 is about 4289.7398522521. The cubic root of 18401868 is about 264.0101580113.

The spelling of 18401868 in words is "eighteen million, four hundred one thousand, eight hundred sixty-eight".