18381330 has 80 divisors (see below), whose sum is σ = 53944704. Its totient is φ = 4453920.

The previous prime is 18381329. The next prime is 18381343. The reversal of 18381330 is 3318381.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 18381294 and 18381303.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7879 + ... + 9941.

Almost surely, 2^18381330 is an apocalyptic number.

18381330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18381330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26972352).

18381330 is an abundant number, since it is smaller than the sum of its proper divisors (35563374).

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

18381330 is a wasteful number, since it uses less digits than its factorization.

18381330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2093 (or 2084 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 18381330 is about 4287.3453324872. The cubic root of 18381330 is about 263.9119024230.

The spelling of 18381330 in words is "eighteen million, three hundred eighty-one thousand, three hundred thirty".