138837240 has 160 divisors (see below), whose sum is σ = 473845680. Its totient is φ = 36453888.

The previous prime is 138837221. The next prime is 138837247. The reversal of 138837240 is 42738831.

138837240 is a `hidden beast` number, since 1 + 388 + 37 + 240 = 666.

138837240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 138837195 and 138837204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138837247) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 236227 + ... + 236813.

Almost surely, 2^138837240 is an apocalyptic number.

138837240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138837240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (236922840).

138837240 is an abundant number, since it is smaller than the sum of its proper divisors (335008440).

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

138837240 is a wasteful number, since it uses less digits than its factorization.

138837240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 683 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 36.

The square root of 138837240 is about 11782.9215392448. The cubic root of 138837240 is about 517.8078823241.

The spelling of 138837240 in words is "one hundred thirty-eight million, eight hundred thirty-seven thousand, two hundred forty".