18261508320 has 672 divisors, whose sum is σ = 72424243584. Its totient is φ = 4311014400.

The previous prime is 18261508261. The next prime is 18261508339. The reversal of 18261508320 is 2380516281.

It is a happy number.

18261508320 is a `hidden beast` number, since 1 + 8 + 2 + 615 + 0 + 8 + 32 + 0 = 666.

It is a super-2 number, since 2×18261508320² (a number of 21 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 55170555 + ... + 55170885.

It is an arithmetic number, because the mean of its divisors is an integer number (107774172).

Almost surely, 2^18261508320 is an apocalyptic number.

18261508320 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 18261508320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36212121792).

18261508320 is an abundant number, since it is smaller than the sum of its proper divisors (54162735264).

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

18261508320 is a wasteful number, since it uses less digits than its factorization.

18261508320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 418 (or 395 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The spelling of 18261508320 in words is "eighteen billion, two hundred sixty-one million, five hundred eight thousand, three hundred twenty".