138443840640 has 768 divisors, whose sum is σ = 566989113600. Its totient is φ = 30470307840.

The previous prime is 138443840611. The next prime is 138443840669. The reversal of 138443840640 is 46048344831.

138443840640 is a `hidden beast` number, since 138 + 4 + 438 + 40 + 6 + 40 = 666.

It is an interprime number because it is at equal distance from previous prime (138443840611) and next prime (138443840669).

It is a super-2 number, since 2×138443840640² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 137208456 + ... + 137209464.

It is an arithmetic number, because the mean of its divisors is an integer number (738267075).

Almost surely, 2^138443840640 is an apocalyptic number.

138443840640 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 138443840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283494556800).

138443840640 is an abundant number, since it is smaller than the sum of its proper divisors (428545272960).

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

138443840640 is a wasteful number, since it uses less digits than its factorization.

138443840640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1165 (or 1150 counting only the distinct ones).

The product of its (nonzero) digits is 884736, while the sum is 45.

The spelling of 138443840640 in words is "one hundred thirty-eight billion, four hundred forty-three million, eight hundred forty thousand, six hundred forty".