138855520 has 96 divisors (see below), whose sum is σ = 342540576. Its totient is φ = 53145600.

The previous prime is 138855517. The next prime is 138855527. The reversal of 138855520 is 25558831.

It is a self number, because there is not a number n which added to its sum of digits gives 138855520.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138855527) 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, 399987 + ... + 400333.

It is an arithmetic number, because the mean of its divisors is an integer number (3568131).

Almost surely, 2^138855520 is an apocalyptic number.

138855520 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 138855520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (171270288).

138855520 is an abundant number, since it is smaller than the sum of its proper divisors (203685056).

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

138855520 is a wasteful number, since it uses less digits than its factorization.

138855520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 464 (or 456 counting only the distinct ones).

The product of its (nonzero) digits is 48000, while the sum is 37.

The square root of 138855520 is about 11783.6972126748. The cubic root of 138855520 is about 517.8306070452.

The spelling of 138855520 in words is "one hundred thirty-eight million, eight hundred fifty-five thousand, five hundred twenty".