138626 has 4 divisors (see below), whose sum is σ = 207942. Its totient is φ = 69312.

The previous prime is 138617. The next prime is 138629. The reversal of 138626 is 626831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 626831 = 53 ⋅11827.

It can be written as a sum of positive squares in only one way, i.e., 75625 + 63001 = 275^2 + 251^2 .

It is a junction number, because it is equal to n+sod(n) for n = 138595 and 138604.

It is not an unprimeable number, because it can be changed into a prime (138629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34655 + ... + 34658.

2¹³⁸⁶²⁶ is an apocalyptic number.

138626 is a deficient number, since it is larger than the sum of its proper divisors (69316).

138626 is an equidigital number, since it uses as much as digits as its factorization.

138626 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69315.

The product of its digits is 1728, while the sum is 26.

The square root of 138626 is about 372.3251267374. The cubic root of 138626 is about 51.7545135195.

The spelling of 138626 in words is "one hundred thirty-eight thousand, six hundred twenty-six".