138445 has 4 divisors (see below), whose sum is σ = 166140. Its totient is φ = 110752.

The previous prime is 138433. The next prime is 138449. The reversal of 138445 is 544831.

138445 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 can be written as a sum of positive squares in 2 ways, for example, as 27556 + 110889 = 166^2 + 333^2 .

It is a cyclic number.

It is not a de Polignac number, because 138445 - 2⁹ = 137933 is a prime.

138445 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138449) 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, 13840 + ... + 13849.

It is an arithmetic number, because the mean of its divisors is an integer number (41535).

2¹³⁸⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

138445 is a deficient number, since it is larger than the sum of its proper divisors (27695).

138445 is an equidigital number, since it uses as much as digits as its factorization.

138445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27694.

The product of its digits is 1920, while the sum is 25.

The square root of 138445 is about 372.0819802140. The cubic root of 138445 is about 51.7319789135.

The spelling of 138445 in words is "one hundred thirty-eight thousand, four hundred forty-five".