138273240 has 256 divisors, whose sum is σ = 525035520. Its totient is φ = 28385280.

The previous prime is 138273227. The next prime is 138273253. The reversal of 138273240 is 42372831.

138273240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (138273227) and next prime (138273253).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 138273198 and 138273207.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 328230 + ... + 328650.

It is an arithmetic number, because the mean of its divisors is an integer number (2050920).

Almost surely, 2^138273240 is an apocalyptic number.

138273240 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 138273240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (262517760).

138273240 is an abundant number, since it is smaller than the sum of its proper divisors (386762280).

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

138273240 is a wasteful number, since it uses less digits than its factorization.

138273240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482 (or 478 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 138273240 is about 11758.9642401021. The cubic root of 138273240 is about 517.1057652315.

The spelling of 138273240 in words is "one hundred thirty-eight million, two hundred seventy-three thousand, two hundred forty".