18307380 has 144 divisors (see below), whose sum is σ = 64350720. Its totient is φ = 3854592.

The previous prime is 18307363. The next prime is 18307397. The reversal of 18307380 is 8370381.

It is an interprime number because it is at equal distance from previous prime (18307363) and next prime (18307397).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 37981 + ... + 38459.

It is an arithmetic number, because the mean of its divisors is an integer number (446880).

Almost surely, 2^18307380 is an apocalyptic number.

18307380 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 18307380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32175360).

18307380 is an abundant number, since it is smaller than the sum of its proper divisors (46043340).

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

18307380 is a wasteful number, since it uses less digits than its factorization.

18307380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 518 (or 509 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 30.

The square root of 18307380 is about 4278.7124231479. The cubic root of 18307380 is about 263.5575117478.

The spelling of 18307380 in words is "eighteen million, three hundred seven thousand, three hundred eighty".