18440619648 has 64 divisors (see below), whose sum is σ = 53435898720. Its totient is φ = 5588065280.

The previous prime is 18440619641. The next prime is 18440619649. The reversal of 18440619648 is 84691604481.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (64).

It is a self number, because there is not a number n which added to its sum of digits gives 18440619648.

It is not an unprimeable number, because it can be changed into a prime (18440619641) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2178615 + ... + 2187062.

Almost surely, 2^18440619648 is an apocalyptic number.

It is an amenable number.

18440619648 is an abundant number, since it is smaller than the sum of its proper divisors (34995279072).

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

18440619648 is a wasteful number, since it uses less digits than its factorization.

18440619648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365705 (or 4365693 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 51.

The spelling of 18440619648 in words is "eighteen billion, four hundred forty million, six hundred nineteen thousand, six hundred forty-eight".