18489238656 has 256 divisors, whose sum is σ = 59471385600. Its totient is φ = 4971663360.

The previous prime is 18489238633. The next prime is 18489238657. The reversal of 18489238656 is 65683298481.

It is a self number, because there is not a number n which added to its sum of digits gives 18489238656.

It is not an unprimeable number, because it can be changed into a prime (18489238657) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8323626 + ... + 8325846.

It is an arithmetic number, because the mean of its divisors is an integer number (232310100).

Almost surely, 2^18489238656 is an apocalyptic number.

18489238656 is a gapful number since it is divisible by the number (16) 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 18489238656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29735692800).

18489238656 is an abundant number, since it is smaller than the sum of its proper divisors (40982146944).

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

18489238656 is a wasteful number, since it uses less digits than its factorization.

18489238656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2427 (or 2415 counting only the distinct ones).

The product of its digits is 19906560, while the sum is 60.

The spelling of 18489238656 in words is "eighteen billion, four hundred eighty-nine million, two hundred thirty-eight thousand, six hundred fifty-six".