138256 has 10 divisors (see below), whose sum is σ = 267902. Its totient is φ = 69120.

The previous prime is 138251. The next prime is 138283. The reversal of 138256 is 652831.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 80656 + 57600 = 284^2 + 240^2 .

It is a super-2 number, since 2×138256² = 38229443072, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 138256.

It is not an unprimeable number, because it can be changed into a prime (138251) by changing a digit.

138256 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 as a sum of consecutive naturals, namely, 4305 + ... + 4336.

2¹³⁸²⁵⁶ is an apocalyptic number.

138256 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

138256 is a deficient number, since it is larger than the sum of its proper divisors (129646).

138256 is an equidigital number, since it uses as much as digits as its factorization.

138256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8649 (or 8643 counting only the distinct ones).

The product of its digits is 1440, while the sum is 25.

The square root of 138256 is about 371.8279171875. The cubic root of 138256 is about 51.7084273307.

It can be divided in two parts, 13825 and 6, that added together give a palindrome (13831).

The spelling of 138256 in words is "one hundred thirty-eight thousand, two hundred fifty-six".