18253818 has 108 divisors (see below), whose sum is σ = 47772270. Its totient is φ = 5026560.

The previous prime is 18253799. The next prime is 18253843. The reversal of 18253818 is 81835281.

It can be written as a sum of positive squares in 3 ways, for example, as 18122049 + 131769 = 4257^2 + 363^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 629428 + ... + 629456.

Almost surely, 2^18253818 is an apocalyptic number.

18253818 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18253818, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23886135).

18253818 is an abundant number, since it is smaller than the sum of its proper divisors (29518452).

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

18253818 is a wasteful number, since it uses less digits than its factorization.

18253818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93 (or 62 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 18253818 is about 4272.4487123897. The cubic root of 18253818 is about 263.3002301318.

The spelling of 18253818 in words is "eighteen million, two hundred fifty-three thousand, eight hundred eighteen".