18218180 has 12 divisors (see below), whose sum is σ = 38258220. Its totient is φ = 7287264.

The previous prime is 18218147. The next prime is 18218191. The reversal of 18218180 is 8181281.

It can be written as a sum of positive squares in 2 ways, for example, as 5373124 + 12845056 = 2318^2 + 3584^2 .

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 3 ways as a sum of consecutive naturals, for example, 455435 + ... + 455474.

It is an arithmetic number, because the mean of its divisors is an integer number (3188185).

Almost surely, 2^18218180 is an apocalyptic number.

18218180 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18218180 is an abundant number, since it is smaller than the sum of its proper divisors (20040040).

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

18218180 is a wasteful number, since it uses less digits than its factorization.

18218180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 910918 (or 910916 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 29.

The square root of 18218180 is about 4268.2759985737. The cubic root of 18218180 is about 263.1287663339.

It can be divided in two parts, 1821 and 8180, that added together give a palindrome (10001).

The spelling of 18218180 in words is "eighteen million, two hundred eighteen thousand, one hundred eighty".