138311387520 has 128 divisors (see below), whose sum is σ = 441241987680. Its totient is φ = 36851712000.

The previous prime is 138311387519. The next prime is 138311387629. The reversal of 138311387520 is 25783113831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a super-2 number, since 2×138311387520² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2275930 + ... + 2335910.

Almost surely, 2^138311387520 is an apocalyptic number.

138311387520 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 138311387520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (220620993840).

138311387520 is an abundant number, since it is smaller than the sum of its proper divisors (302930600160).

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

138311387520 is a wasteful number, since it uses less digits than its factorization.

138311387520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61204 (or 61192 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 42.

The spelling of 138311387520 in words is "one hundred thirty-eight billion, three hundred eleven million, three hundred eighty-seven thousand, five hundred twenty".