138638344 has 64 divisors (see below), whose sum is σ = 289578240. Its totient is φ = 61824000.

The previous prime is 138638341. The next prime is 138638347. The reversal of 138638344 is 443836831.

It is an interprime number because it is at equal distance from previous prime (138638341) and next prime (138638347).

It is a junction number, because it is equal to n+sod(n) for n = 138638297 and 138638306.

It is not an unprimeable number, because it can be changed into a prime (138638341) 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, 552219 + ... + 552469.

It is an arithmetic number, because the mean of its divisors is an integer number (4524660).

Almost surely, 2^138638344 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 138638344, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (144789120).

138638344 is an abundant number, since it is smaller than the sum of its proper divisors (150939896).

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

138638344 is a wasteful number, since it uses less digits than its factorization.

138638344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430 (or 426 counting only the distinct ones).

The product of its digits is 165888, while the sum is 40.

The square root of 138638344 is about 11774.4785022522. The cubic root of 138638344 is about 517.5604964011.

The spelling of 138638344 in words is "one hundred thirty-eight million, six hundred thirty-eight thousand, three hundred forty-four".