18089778 has 16 divisors (see below), whose sum is σ = 41348160. Its totient is φ = 5168496.

The previous prime is 18089737. The next prime is 18089789. The reversal of 18089778 is 87798081.

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, 215313 + ... + 215396.

It is an arithmetic number, because the mean of its divisors is an integer number (2584260).

Almost surely, 2^18089778 is an apocalyptic number.

18089778 is an abundant number, since it is smaller than the sum of its proper divisors (23258382).

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

18089778 is a wasteful number, since it uses less digits than its factorization.

18089778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430721.

The product of its (nonzero) digits is 225792, while the sum is 48.

The square root of 18089778 is about 4253.2079657595. The cubic root of 18089778 is about 262.5091298412.

The spelling of 18089778 in words is "eighteen million, eighty-nine thousand, seven hundred seventy-eight".