18218144 has 24 divisors (see below), whose sum is σ = 40991328. Its totient is φ = 7807680.

The previous prime is 18218143. The next prime is 18218147. The reversal of 18218144 is 44181281.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (18218143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40442 + ... + 40889.

It is an arithmetic number, because the mean of its divisors is an integer number (1707972).

Almost surely, 2^18218144 is an apocalyptic number.

18218144 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

18218144 is an abundant number, since it is smaller than the sum of its proper divisors (22773184).

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

18218144 is an equidigital number, since it uses as much as digits as its factorization.

18218144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81348 (or 81340 counting only the distinct ones).

The product of its digits is 2048, while the sum is 29.

The square root of 18218144 is about 4268.2717814122. The cubic root of 18218144 is about 263.1285930154.

The spelling of 18218144 in words is "eighteen million, two hundred eighteen thousand, one hundred forty-four".