138255907 has 4 divisors (see below), whose sum is σ = 140319496. Its totient is φ = 136192320.

The previous prime is 138255881. The next prime is 138255919. The reversal of 138255907 is 709552831.

138255907 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138255907 - 2¹¹ = 138253859 is a prime.

It is a super-2 number, since 2×138255907² = 38229391640785298, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138255907.

It is not an unprimeable number, because it can be changed into a prime (138255937) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1031694 + ... + 1031827.

It is an arithmetic number, because the mean of its divisors is an integer number (35079874).

Almost surely, 2^138255907 is an apocalyptic number.

138255907 is a deficient number, since it is larger than the sum of its proper divisors (2063589).

138255907 is an equidigital number, since it uses as much as digits as its factorization.

138255907 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2063588.

The product of its (nonzero) digits is 75600, while the sum is 40.

The square root of 138255907 is about 11758.2272048128. The cubic root of 138255907 is about 517.0841573659.

The spelling of 138255907 in words is "one hundred thirty-eight million, two hundred fifty-five thousand, nine hundred seven".