138840440 has 16 divisors (see below), whose sum is σ = 312391080. Its totient is φ = 55536160.

The previous prime is 138840437. The next prime is 138840451. The reversal of 138840440 is 44048831.

It is a junction number, because it is equal to n+sod(n) for n = 138840397 and 138840406.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1735466 + ... + 1735545.

Almost surely, 2^138840440 is an apocalyptic number.

138840440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138840440 is an abundant number, since it is smaller than the sum of its proper divisors (173550640).

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

138840440 is a wasteful number, since it uses less digits than its factorization.

138840440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3471022 (or 3471018 counting only the distinct ones).

The product of its (nonzero) digits is 12288, while the sum is 32.

The square root of 138840440 is about 11783.0573282149. The cubic root of 138840440 is about 517.8118605375.

The spelling of 138840440 in words is "one hundred thirty-eight million, eight hundred forty thousand, four hundred forty".