18188180 has 12 divisors (see below), whose sum is σ = 38195220. Its totient is φ = 7275264.

The previous prime is 18188173. The next prime is 18188189. The reversal of 18188180 is 8188181.

It can be written as a sum of positive squares in 2 ways, for example, as 12418576 + 5769604 = 3524^2 + 2402^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18188180.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18188189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 454685 + ... + 454724.

It is an arithmetic number, because the mean of its divisors is an integer number (3182935).

Almost surely, 2^18188180 is an apocalyptic number.

18188180 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18188180 is an abundant number, since it is smaller than the sum of its proper divisors (20007040).

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

18188180 is a wasteful number, since it uses less digits than its factorization.

18188180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 909418 (or 909416 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 35.

The square root of 18188180 is about 4264.7602511747. The cubic root of 18188180 is about 262.9842550102.

Subtracting from 18188180 its reverse (8188181), we obtain a palindrome (9999999).

The spelling of 18188180 in words is "eighteen million, one hundred eighty-eight thousand, one hundred eighty".