138444 has 24 divisors (see below), whose sum is σ = 329280. Its totient is φ = 45264.

The previous prime is 138433. The next prime is 138449. The reversal of 138444 is 444831.

138444 = 120² + 121² + ... + 128².

It is a super-2 number, since 2×138444² = 38333482272, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 138444.

It is not an unprimeable number, because it can be changed into a prime (138449) 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, 927 + ... + 1065.

It is an arithmetic number, because the mean of its divisors is an integer number (13720).

2¹³⁸⁴⁴⁴ is an apocalyptic number.

It is an amenable number.

138444 is an abundant number, since it is smaller than the sum of its proper divisors (190836).

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

138444 is a wasteful number, since it uses less digits than its factorization.

138444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 229 (or 227 counting only the distinct ones).

The product of its digits is 1536, while the sum is 24.

The square root of 138444 is about 372.0806364217. The cubic root of 138444 is about 51.7318543584.

The spelling of 138444 in words is "one hundred thirty-eight thousand, four hundred forty-four".