18509368320 has 792 divisors, whose sum is σ = 72520297200. Its totient is φ = 4514807808.

The previous prime is 18509368303. The next prime is 18509368321. The reversal of 18509368320 is 2386390581.

It is a happy number.

18509368320 is a `hidden beast` number, since 18 + 509 + 36 + 83 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (18509368321) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 638254066 + ... + 638254094.

Almost surely, 2^18509368320 is an apocalyptic number.

18509368320 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 18509368320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36260148600).

18509368320 is an abundant number, since it is smaller than the sum of its proper divisors (54010928880).

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

18509368320 is an frugal number, since it uses more digits than its factorization.

18509368320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 18509368320 in words is "eighteen billion, five hundred nine million, three hundred sixty-eight thousand, three hundred twenty".