138257181 has 24 divisors (see below), whose sum is σ = 207263160. Its totient is φ = 88704000.

The previous prime is 138257177. The next prime is 138257219. The reversal of 138257181 is 181752831.

138257181 is a `hidden beast` number, since 1 + 3 + 8 + 2 + 571 + 81 = 666.

138257181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 98188281 + 40068900 = 9909^2 + 6330^2 .

It is not a de Polignac number, because 138257181 - 2² = 138257177 is a prime.

It is a super-2 number, since 2×138257181² = 38230096196133522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138257111) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 104001 + ... + 105321.

It is an arithmetic number, because the mean of its divisors is an integer number (8635965).

Almost surely, 2^138257181 is an apocalyptic number.

It is an amenable number.

138257181 is a deficient number, since it is larger than the sum of its proper divisors (69005979).

138257181 is a wasteful number, since it uses less digits than its factorization.

138257181 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1757 (or 1754 counting only the distinct ones).

The product of its digits is 13440, while the sum is 36.

The square root of 138257181 is about 11758.2813795214. The cubic root of 138257181 is about 517.0857456360.

The spelling of 138257181 in words is "one hundred thirty-eight million, two hundred fifty-seven thousand, one hundred eighty-one".