138721656960 has 576 divisors, whose sum is σ = 521420328000. Its totient is φ = 33889259520.

The previous prime is 138721656959. The next prime is 138721657013. The reversal of 138721656960 is 69656127831.

138721656960 is a `hidden beast` number, since 1 + 3 + 8 + 7 + 2 + 16 + 569 + 60 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a junction number, because it is equal to n+sod(n) for n = 138721656897 and 138721656906.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 105171181 + ... + 105172499.

It is an arithmetic number, because the mean of its divisors is an integer number (905243625).

Almost surely, 2^138721656960 is an apocalyptic number.

138721656960 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 138721656960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (260710164000).

138721656960 is an abundant number, since it is smaller than the sum of its proper divisors (382698671040).

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

138721656960 is a wasteful number, since it uses less digits than its factorization.

138721656960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1425 (or 1379 counting only the distinct ones).

The product of its (nonzero) digits is 3265920, while the sum is 54.

The spelling of 138721656960 in words is "one hundred thirty-eight billion, seven hundred twenty-one million, six hundred fifty-six thousand, nine hundred sixty".