18380388 has 48 divisors (see below), whose sum is σ = 46992960. Its totient is φ = 5556864.

The previous prime is 18380339. The next prime is 18380389. The reversal of 18380388 is 88308381.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18380389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8206 + ... + 10202.

It is an arithmetic number, because the mean of its divisors is an integer number (979020).

Almost surely, 2^18380388 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18380388, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23496480).

18380388 is an abundant number, since it is smaller than the sum of its proper divisors (28612572).

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

18380388 is a wasteful number, since it uses less digits than its factorization.

18380388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2076 (or 2074 counting only the distinct ones).

The product of its (nonzero) digits is 36864, while the sum is 39.

The square root of 18380388 is about 4287.2354728893. The cubic root of 18380388 is about 263.9073940576.

The spelling of 18380388 in words is "eighteen million, three hundred eighty thousand, three hundred eighty-eight".