18315621665516 has 48 divisors (see below), whose sum is σ = 36675469286400. Its totient is φ = 7840079166528.

The previous prime is 18315621665513. The next prime is 18315621665519. The reversal of 18315621665516 is 61556612651381.

It is an interprime number because it is at equal distance from previous prime (18315621665513) and next prime (18315621665519).

It is not an unprimeable number, because it can be changed into a prime (18315621665513) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 112672625 + ... + 112835063.

It is an arithmetic number, because the mean of its divisors is an integer number (764072276800).

Almost surely, 2^{18315621665516} is an apocalyptic number.

It is an amenable number.

18315621665516 is an abundant number, since it is smaller than the sum of its proper divisors (18359847620884).

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

18315621665516 is a wasteful number, since it uses less digits than its factorization.

18315621665516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167286 (or 167284 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 56.

The spelling of 18315621665516 in words is "eighteen trillion, three hundred fifteen billion, six hundred twenty-one million, six hundred sixty-five thousand, five hundred sixteen".