18213390 has 64 divisors (see below), whose sum is σ = 52315200. Its totient is φ = 4482432.

The previous prime is 18213383. The next prime is 18213449. The reversal of 18213390 is 9331281.

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

It is a congruent number.

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, 916 + ... + 6104.

It is an arithmetic number, because the mean of its divisors is an integer number (817425).

Almost surely, 2^18213390 is an apocalyptic number.

18213390 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 18213390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26157600).

18213390 is an abundant number, since it is smaller than the sum of its proper divisors (34101810).

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

18213390 is a wasteful number, since it uses less digits than its factorization.

18213390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5218 (or 5212 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 27.

The square root of 18213390 is about 4267.7148452070. The cubic root of 18213390 is about 263.1057033409.

The spelling of 18213390 in words is "eighteen million, two hundred thirteen thousand, three hundred ninety".