18165420 has 144 divisors (see below), whose sum is σ = 67878720. Its totient is φ = 3829248.

The previous prime is 18165391. The next prime is 18165431. The reversal of 18165420 is 2456181.

18165420 is a `hidden beast` number, since 1 + 8 + 1 + 654 + 2 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 15826 + ... + 16934.

It is an arithmetic number, because the mean of its divisors is an integer number (471380).

Almost surely, 2^18165420 is an apocalyptic number.

18165420 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18165420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33939360).

18165420 is an abundant number, since it is smaller than the sum of its proper divisors (49713300).

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

18165420 is a wasteful number, since it uses less digits than its factorization.

18165420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1144 (or 1139 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 18165420 is about 4262.0910360995. The cubic root of 18165420 is about 262.8745130411.

The spelling of 18165420 in words is "eighteen million, one hundred sixty-five thousand, four hundred twenty".