18805820 has 72 divisors (see below), whose sum is σ = 45805200. Its totient is φ = 6462720.

The previous prime is 18805811. The next prime is 18805849. The reversal of 18805820 is 2850881.

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 45776 + ... + 46184.

Almost surely, 2^18805820 is an apocalyptic number.

18805820 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 18805820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22902600).

18805820 is an abundant number, since it is smaller than the sum of its proper divisors (26999380).

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

18805820 is a wasteful number, since it uses less digits than its factorization.

18805820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459 (or 446 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 32.

The square root of 18805820 is about 4336.5677672556. The cubic root of 18805820 is about 265.9280148927.

The spelling of 18805820 in words is "eighteen million, eight hundred five thousand, eight hundred twenty".