18135864 has 24 divisors (see below), whose sum is σ = 49118160. Its totient is φ = 6045264.

The previous prime is 18135853. The next prime is 18135881. The reversal of 18135864 is 46853181.

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

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

It is a congruent number.

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, 125872 + ... + 126015.

It is an arithmetic number, because the mean of its divisors is an integer number (2046590).

Almost surely, 2^18135864 is an apocalyptic number.

It is an amenable number.

18135864 is an abundant number, since it is smaller than the sum of its proper divisors (30982296).

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

18135864 is a wasteful number, since it uses less digits than its factorization.

18135864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251899 (or 251892 counting only the distinct ones).

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

The square root of 18135864 is about 4258.6223124386. The cubic root of 18135864 is about 262.7318658812.

The spelling of 18135864 in words is "eighteen million, one hundred thirty-five thousand, eight hundred sixty-four".