138257285 has 8 divisors (see below), whose sum is σ = 166052376. Its totient is φ = 110510080.

The previous prime is 138257263. The next prime is 138257321. The reversal of 138257285 is 582752831.

It can be written as a sum of positive squares in 4 ways, for example, as 4669921 + 133587364 = 2161^2 + 11558^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138257285 - 2⁸ = 138257029 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 (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5276 + ... + 17445.

It is an arithmetic number, because the mean of its divisors is an integer number (20756547).

Almost surely, 2^138257285 is an apocalyptic number.

It is an amenable number.

138257285 is a deficient number, since it is larger than the sum of its proper divisors (27795091).

138257285 is a wasteful number, since it uses less digits than its factorization.

138257285 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23943.

The product of its digits is 134400, while the sum is 41.

The square root of 138257285 is about 11758.2858019356. The cubic root of 138257285 is about 517.0858752903.

The spelling of 138257285 in words is "one hundred thirty-eight million, two hundred fifty-seven thousand, two hundred eighty-five".