18390000 has 100 divisors (see below), whose sum is σ = 59462216. Its totient is φ = 4896000.

The previous prime is 18389989. The next prime is 18390013. The reversal of 18390000 is 9381.

It is a tau number, because it is divible by the number of its divisors (100).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 29694 + ... + 30306.

Almost surely, 2^18390000 is an apocalyptic number.

18390000 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 18390000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29731108).

18390000 is an abundant number, since it is smaller than the sum of its proper divisors (41072216).

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

18390000 is an equidigital number, since it uses as much as digits as its factorization.

18390000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 644 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 18390000 is about 4288.3563284783. The cubic root of 18390000 is about 263.9533893836.

Adding to 18390000 its reverse (9381), we get a palindrome (18399381).

The spelling of 18390000 in words is "eighteen million, three hundred ninety thousand".