138240444 has 12 divisors (see below), whose sum is σ = 322561064. Its totient is φ = 46080144.

The previous prime is 138240391. The next prime is 138240491. The reversal of 138240444 is 444042831.

138240444 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×138240444² = 38220840714634272, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5760007 + ... + 5760030.

Almost surely, 2^138240444 is an apocalyptic number.

It is an amenable number.

138240444 is an abundant number, since it is smaller than the sum of its proper divisors (184320620).

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

138240444 is a wasteful number, since it uses less digits than its factorization.

138240444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11520044 (or 11520042 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 30.

The square root of 138240444 is about 11757.5696468275. The cubic root of 138240444 is about 517.0648791771.

The spelling of 138240444 in words is "one hundred thirty-eight million, two hundred forty thousand, four hundred forty-four".