18320208840 has 96 divisors (see below), whose sum is σ = 59655136320. Its totient is φ = 4875997824.

The previous prime is 18320208839. The next prime is 18320208857. The reversal of 18320208840 is 4880202381.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 18320208795 and 18320208804.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 139629 + ... + 236931.

It is an arithmetic number, because the mean of its divisors is an integer number (621407670).

Almost surely, 2^18320208840 is an apocalyptic number.

18320208840 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 18320208840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29827568160).

18320208840 is an abundant number, since it is smaller than the sum of its proper divisors (41334927480).

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

18320208840 is a wasteful number, since it uses less digits than its factorization.

18320208840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97843 (or 97836 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The spelling of 18320208840 in words is "eighteen billion, three hundred twenty million, two hundred eight thousand, eight hundred forty".