138209255 has 4 divisors (see below), whose sum is σ = 165851112. Its totient is φ = 110567400.

The previous prime is 138209233. The next prime is 138209261. The reversal of 138209255 is 552902831.

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

It is a de Polignac number, because none of the positive numbers 2^k-138209255 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13820921 + ... + 13820930.

It is an arithmetic number, because the mean of its divisors is an integer number (41462778).

Almost surely, 2^138209255 is an apocalyptic number.

138209255 is a deficient number, since it is larger than the sum of its proper divisors (27641857).

138209255 is an equidigital number, since it uses as much as digits as its factorization.

138209255 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27641856.

The product of its (nonzero) digits is 21600, while the sum is 35.

The square root of 138209255 is about 11756.2432349794. The cubic root of 138209255 is about 517.0259905349.

The spelling of 138209255 in words is "one hundred thirty-eight million, two hundred nine thousand, two hundred fifty-five".