138888455440 has 160 divisors (see below), whose sum is σ = 385666744320. Its totient is φ = 45521505792.

The previous prime is 138888455401. The next prime is 138888455441. The reversal of 138888455440 is 44554888831.

It is not an unprimeable number, because it can be changed into a prime (138888455441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1070401 + ... + 1193119.

It is an arithmetic number, because the mean of its divisors is an integer number (2410417152).

Almost surely, 2^138888455440 is an apocalyptic number.

138888455440 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 138888455440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (192833372160).

138888455440 is an abundant number, since it is smaller than the sum of its proper divisors (246778288880).

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

138888455440 is a wasteful number, since it uses less digits than its factorization.

138888455440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 122829 (or 122823 counting only the distinct ones).

The product of its (nonzero) digits is 19660800, while the sum is 58.

The spelling of 138888455440 in words is "one hundred thirty-eight billion, eight hundred eighty-eight million, four hundred fifty-five thousand, four hundred forty".