18015666522 has 128 divisors (see below), whose sum is σ = 43117608960. Its totient is φ = 4911217920.

The previous prime is 18015666521. The next prime is 18015666589. The reversal of 18015666522 is 22566651081.

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

It is not an unprimeable number, because it can be changed into a prime (18015666521) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 29679543 + ... + 29680149.

It is an arithmetic number, because the mean of its divisors is an integer number (336856320).

Almost surely, 2^18015666522 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18015666522, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21558804480).

18015666522 is an abundant number, since it is smaller than the sum of its proper divisors (25101942438).

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

18015666522 is a wasteful number, since it uses less digits than its factorization.

18015666522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 996.

The product of its (nonzero) digits is 172800, while the sum is 42.

The spelling of 18015666522 in words is "eighteen billion, fifteen million, six hundred sixty-six thousand, five hundred twenty-two".