18245556 has 72 divisors (see below), whose sum is σ = 55823040. Its totient is φ = 4905216.

The previous prime is 18245503. The next prime is 18245581. The reversal of 18245556 is 65554281.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 18245556.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2155 + ... + 6413.

It is an arithmetic number, because the mean of its divisors is an integer number (775320).

Almost surely, 2^18245556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18245556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27911520).

18245556 is an abundant number, since it is smaller than the sum of its proper divisors (37577484).

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

18245556 is a wasteful number, since it uses less digits than its factorization.

18245556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4293 (or 4288 counting only the distinct ones).

The product of its digits is 48000, while the sum is 36.

The square root of 18245556 is about 4271.4817101329. The cubic root of 18245556 is about 263.2604993607.

The spelling of 18245556 in words is "eighteen million, two hundred forty-five thousand, five hundred fifty-six".