18398380 has 96 divisors (see below), whose sum is σ = 51932160. Its totient is φ = 5287680.

The previous prime is 18398353. The next prime is 18398417. The reversal of 18398380 is 8389381.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 19561 + ... + 20479.

It is an arithmetic number, because the mean of its divisors is an integer number (540960).

Almost surely, 2^18398380 is an apocalyptic number.

18398380 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 18398380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25966080).

18398380 is an abundant number, since it is smaller than the sum of its proper divisors (33533780).

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

18398380 is a wasteful number, since it uses less digits than its factorization.

18398380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 959 (or 957 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 18398380 is about 4289.3332815252. Note that the first 3 decimals coincide. The cubic root of 18398380 is about 263.9934762698.

The spelling of 18398380 in words is "eighteen million, three hundred ninety-eight thousand, three hundred eighty".