18159888640 has 72 divisors (see below), whose sum is σ = 43538512248. Its totient is φ = 7257292800.

The previous prime is 18159888611. The next prime is 18159888667. The reversal of 18159888640 is 4688895181.

It can be written as a sum of positive squares in 4 ways, for example, as 199600384 + 17960288256 = 14128^2 + 134016^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1531374 + ... + 1543186.

It is an arithmetic number, because the mean of its divisors is an integer number (604701559).

Almost surely, 2^18159888640 is an apocalyptic number.

18159888640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18159888640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21769256124).

18159888640 is an abundant number, since it is smaller than the sum of its proper divisors (25378623608).

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

18159888640 is a wasteful number, since it uses less digits than its factorization.

18159888640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13035 (or 13021 counting only the distinct ones).

The product of its (nonzero) digits is 4423680, while the sum is 58.

The spelling of 18159888640 in words is "eighteen billion, one hundred fifty-nine million, eight hundred eighty-eight thousand, six hundred forty".