138900240 has 60 divisors (see below), whose sum is σ = 466475724. Its totient is φ = 37039872.

The previous prime is 138900221. The next prime is 138900247. The reversal of 138900240 is 42009831.

It can be written as a sum of positive squares in 2 ways, for example, as 107495424 + 31404816 = 10368^2 + 5604^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is not an unprimeable number, because it can be changed into a prime (138900247) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 95739 + ... + 97178.

Almost surely, 2^138900240 is an apocalyptic number.

138900240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138900240 is an abundant number, since it is smaller than the sum of its proper divisors (327575484).

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

138900240 is a wasteful number, since it uses less digits than its factorization.

138900240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 192936 (or 192927 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 138900240 is about 11785.5945967949. The cubic root of 138900240 is about 517.8861921579.

The spelling of 138900240 in words is "one hundred thirty-eight million, nine hundred thousand, two hundred forty".