138140640 has 576 divisors, whose sum is σ = 594397440. Its totient is φ = 29859840.

The previous prime is 138140627. The next prime is 138140641. The reversal of 138140640 is 46041831.

138140640 is a `hidden beast` number, since 1 + 3 + 8 + 14 + 0 + 640 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138140641) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 7270551 + ... + 7270569.

It is an arithmetic number, because the mean of its divisors is an integer number (1031940).

Almost surely, 2^138140640 is an apocalyptic number.

138140640 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 138140640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (297198720).

138140640 is an abundant number, since it is smaller than the sum of its proper divisors (456256800).

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

138140640 is a wasteful number, since it uses less digits than its factorization.

138140640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 57 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 138140640 is about 11753.3246360338. The cubic root of 138140640 is about 516.9404159215.

The spelling of 138140640 in words is "one hundred thirty-eight million, one hundred forty thousand, six hundred forty".