138800640 has 320 divisors, whose sum is σ = 509110272. Its totient is φ = 31948800.

The previous prime is 138800639. The next prime is 138800647. The reversal of 138800640 is 46008831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (320).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 138800598 and 138800607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138800647) 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, 2618854 + ... + 2618906.

Almost surely, 2^138800640 is an apocalyptic number.

138800640 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 138800640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (254555136).

138800640 is an abundant number, since it is smaller than the sum of its proper divisors (370309632).

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

138800640 is a wasteful number, since it uses less digits than its factorization.

138800640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 105 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 138800640 is about 11781.3683415807. The cubic root of 138800640 is about 517.7623771602.

The spelling of 138800640 in words is "one hundred thirty-eight million, eight hundred thousand, six hundred forty".