138577920 has 192 divisors, whose sum is σ = 478820160. Its totient is φ = 34013184.

The previous prime is 138577883. The next prime is 138577927. The reversal of 138577920 is 29775831.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (138577927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399187 + ... + 399533.

It is an arithmetic number, because the mean of its divisors is an integer number (2493855).

Almost surely, 2^138577920 is an apocalyptic number.

138577920 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 138577920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (239410080).

138577920 is an abundant number, since it is smaller than the sum of its proper divisors (340242240).

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

138577920 is a wasteful number, since it uses less digits than its factorization.

138577920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 370 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 42.

The square root of 138577920 is about 11771.9123340263. The cubic root of 138577920 is about 517.4852944548.

The spelling of 138577920 in words is "one hundred thirty-eight million, five hundred seventy-seven thousand, nine hundred twenty".