18213618 has 16 divisors (see below), whose sum is σ = 36491616. Its totient is φ = 6060480.

The previous prime is 18213617. The next prime is 18213659. The reversal of 18213618 is 81631281.

It is not an unprimeable number, because it can be changed into a prime (18213617) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1498 + ... + 6218.

It is an arithmetic number, because the mean of its divisors is an integer number (2280726).

Almost surely, 2^18213618 is an apocalyptic number.

18213618 is an abundant number, since it is smaller than the sum of its proper divisors (18277998).

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

18213618 is a wasteful number, since it uses less digits than its factorization.

18213618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5369.

The product of its digits is 2304, while the sum is 30.

The square root of 18213618 is about 4267.7415573111. The cubic root of 18213618 is about 263.1068012118.

Adding to 18213618 its reverse (81631281), we get a palindrome (99844899).

The spelling of 18213618 in words is "eighteen million, two hundred thirteen thousand, six hundred eighteen".