138501720 has 384 divisors, whose sum is σ = 564071040. Its totient is φ = 28753920.

The previous prime is 138501679. The next prime is 138501721. The reversal of 138501720 is 27105831.

138501720 is a `hidden beast` number, since 138 + 501 + 7 + 20 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138501721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2270490 + ... + 2270550.

It is an arithmetic number, because the mean of its divisors is an integer number (1468935).

Almost surely, 2^138501720 is an apocalyptic number.

138501720 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 138501720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (282035520).

138501720 is an abundant number, since it is smaller than the sum of its proper divisors (425569320).

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

138501720 is a wasteful number, since it uses less digits than its factorization.

138501720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 138501720 is about 11768.6753715106. The cubic root of 138501720 is about 517.3904269867.

The spelling of 138501720 in words is "one hundred thirty-eight million, five hundred one thousand, seven hundred twenty".