18621644118 has 128 divisors (see below), whose sum is σ = 47532441600. Its totient is φ = 4722779520.

The previous prime is 18621644057. The next prime is 18621644137. The reversal of 18621644118 is 81144612681.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 18621644118.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13309983 + ... + 13311381.

It is an arithmetic number, because the mean of its divisors is an integer number (371347200).

Almost surely, 2^18621644118 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18621644118, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23766220800).

18621644118 is an abundant number, since it is smaller than the sum of its proper divisors (28910797482).

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

18621644118 is a wasteful number, since it uses less digits than its factorization.

18621644118 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2082.

The product of its digits is 73728, while the sum is 42.

The spelling of 18621644118 in words is "eighteen billion, six hundred twenty-one million, six hundred forty-four thousand, one hundred eighteen".