138634669440 has 768 divisors, whose sum is σ = 510393312000. Its totient is φ = 34633138176.

The previous prime is 138634669423. The next prime is 138634669451. The reversal of 138634669440 is 44966436831.

It is a happy number.

138634669440 is a `hidden beast` number, since 1 + 38 + 63 + 466 + 94 + 4 + 0 = 666.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 774495271 + ... + 774495449.

It is an arithmetic number, because the mean of its divisors is an integer number (664574625).

Almost surely, 2^138634669440 is an apocalyptic number.

138634669440 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 138634669440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255196656000).

138634669440 is an abundant number, since it is smaller than the sum of its proper divisors (371758642560).

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

138634669440 is a wasteful number, since it uses less digits than its factorization.

138634669440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 359 (or 344 counting only the distinct ones).

The product of its (nonzero) digits is 8957952, while the sum is 54.

The spelling of 138634669440 in words is "one hundred thirty-eight billion, six hundred thirty-four million, six hundred sixty-nine thousand, four hundred forty".