18338838 has 80 divisors (see below), whose sum is σ = 45712320. Its totient is φ = 4889808.

The previous prime is 18338833. The next prime is 18338867. The reversal of 18338838 is 83883381.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 18338838.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18338833) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 273681 + ... + 273747.

It is an arithmetic number, because the mean of its divisors is an integer number (571404).

Almost surely, 2^18338838 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18338838, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22856160).

18338838 is an abundant number, since it is smaller than the sum of its proper divisors (27373482).

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

18338838 is an equidigital number, since it uses as much as digits as its factorization.

18338838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 119 (or 98 counting only the distinct ones).

The product of its digits is 110592, while the sum is 42.

The square root of 18338838 is about 4282.3869512224. The cubic root of 18338838 is about 263.7083843806.

The spelling of 18338838 in words is "eighteen million, three hundred thirty-eight thousand, eight hundred thirty-eight".