18956615808 has 128 divisors (see below), whose sum is σ = 54283078080. Its totient is φ = 5826760704.

The previous prime is 18956615789. The next prime is 18956615831. The reversal of 18956615808 is 80851665981.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8450335 + ... + 8452577.

Almost surely, 2^18956615808 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18956615808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27141539040).

18956615808 is an abundant number, since it is smaller than the sum of its proper divisors (35326462272).

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

18956615808 is a wasteful number, since it uses less digits than its factorization.

18956615808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3966 (or 3954 counting only the distinct ones).

The product of its (nonzero) digits is 4147200, while the sum is 57.

The spelling of 18956615808 in words is "eighteen billion, nine hundred fifty-six million, six hundred fifteen thousand, eight hundred eight".