138535680 has 144 divisors (see below), whose sum is σ = 453277440. Its totient is φ = 36040704.

The previous prime is 138535673. The next prime is 138535681. The reversal of 138535680 is 86535831.

It is not an unprimeable number, because it can be changed into a prime (138535681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 164701 + ... + 165539.

It is an arithmetic number, because the mean of its divisors is an integer number (3147760).

Almost surely, 2^138535680 is an apocalyptic number.

138535680 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 138535680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (226638720).

138535680 is an abundant number, since it is smaller than the sum of its proper divisors (314741760).

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

138535680 is an equidigital number, since it uses as much as digits as its factorization.

138535680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 906 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 138535680 is about 11770.1180962639. The cubic root of 138535680 is about 517.4327108010.

The spelling of 138535680 in words is "one hundred thirty-eight million, five hundred thirty-five thousand, six hundred eighty".