138864 has 40 divisors (see below), whose sum is σ = 392832. Its totient is φ = 41920.

The previous prime is 138863. The next prime is 138869. The reversal of 138864 is 468831.

It is a happy number.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138863) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 397 + ... + 659.

2¹³⁸⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (196416).

138864 is an abundant number, since it is smaller than the sum of its proper divisors (253968).

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

138864 is a wasteful number, since it uses less digits than its factorization.

138864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285 (or 279 counting only the distinct ones).

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

The square root of 138864 is about 372.6446028054. The cubic root of 138864 is about 51.7841148252.

The spelling of 138864 in words is "one hundred thirty-eight thousand, eight hundred sixty-four".