18138432 has 112 divisors (see below), whose sum is σ = 53197760. Its totient is φ = 5451264.

The previous prime is 18138409. The next prime is 18138437. The reversal of 18138432 is 23483181.

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 18138432.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18138437) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 421803 + ... + 421845.

It is an arithmetic number, because the mean of its divisors is an integer number (474980).

Almost surely, 2^18138432 is an apocalyptic number.

18138432 is a gapful number since it is divisible by the number (12) 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 18138432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26598880).

18138432 is an abundant number, since it is smaller than the sum of its proper divisors (35059328).

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

18138432 is an equidigital number, since it uses as much as digits as its factorization.

18138432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97 (or 61 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 18138432 is about 4258.9238077242. The cubic root of 18138432 is about 262.7442660548.

The spelling of 18138432 in words is "eighteen million, one hundred thirty-eight thousand, four hundred thirty-two".