18516402240 has 448 divisors, whose sum is σ = 69918681600. Its totient is φ = 4148551680.

The previous prime is 18516402239. The next prime is 18516402251. The reversal of 18516402240 is 4220461581.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (448).

It is a hoax number, since the sum of its digits (33) coincides with the sum of the digits of its distinct prime factors.

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, 17451310 + ... + 17452370.

Almost surely, 2^18516402240 is an apocalyptic number.

18516402240 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 18516402240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34959340800).

18516402240 is an abundant number, since it is smaller than the sum of its proper divisors (51402279360).

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

18516402240 is a wasteful number, since it uses less digits than its factorization.

18516402240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1155 (or 1131 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 33.

The spelling of 18516402240 in words is "eighteen billion, five hundred sixteen million, four hundred two thousand, two hundred forty".