18268820 has 12 divisors (see below), whose sum is σ = 38364564. Its totient is φ = 7307520.

The previous prime is 18268807. The next prime is 18268849. The reversal of 18268820 is 2886281.

It can be written as a sum of positive squares in 2 ways, for example, as 2172676 + 16096144 = 1474^2 + 4012^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 456701 + ... + 456740.

It is an arithmetic number, because the mean of its divisors is an integer number (3197047).

Almost surely, 2^18268820 is an apocalyptic number.

18268820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18268820 is an abundant number, since it is smaller than the sum of its proper divisors (20095744).

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

18268820 is a wasteful number, since it uses less digits than its factorization.

18268820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 913450 (or 913448 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 35.

The square root of 18268820 is about 4274.2040194637. The cubic root of 18268820 is about 263.3723419575.

The spelling of 18268820 in words is "eighteen million, two hundred sixty-eight thousand, eight hundred twenty".