138432 has 56 divisors (see below), whose sum is σ = 422656. Its totient is φ = 39168.

The previous prime is 138427. The next prime is 138433. The reversal of 138432 is 234831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (21).

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

It is a junction number, because it is equal to n+sod(n) for n = 138399 and 138408.

It is not an unprimeable number, because it can be changed into a prime (138433) by changing a digit.

138432 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1293 + ... + 1395.

2¹³⁸⁴³² is an apocalyptic number.

138432 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 138432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (211328).

138432 is an abundant number, since it is smaller than the sum of its proper divisors (284224).

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

138432 is a wasteful number, since it uses less digits than its factorization.

138432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125 (or 115 counting only the distinct ones).

The product of its digits is 576, while the sum is 21.

The square root of 138432 is about 372.0645105355. The cubic root of 138432 is about 51.7303596500.

The spelling of 138432 in words is "one hundred thirty-eight thousand, four hundred thirty-two".