138745 has 4 divisors (see below), whose sum is σ = 166500. Its totient is φ = 110992.

The previous prime is 138739. The next prime is 138763. The reversal of 138745 is 547831.

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 43264 + 95481 = 208^2 + 309^2 .

It is a cyclic number.

It is not a de Polignac number, because 138745 - 2⁷ = 138617 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13870 + ... + 13879.

It is an arithmetic number, because the mean of its divisors is an integer number (41625).

2¹³⁸⁷⁴⁵ is an apocalyptic number.

It is an amenable number.

138745 is a deficient number, since it is larger than the sum of its proper divisors (27755).

138745 is an equidigital number, since it uses as much as digits as its factorization.

138745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27754.

The product of its digits is 3360, while the sum is 28.

The square root of 138745 is about 372.4848990228. The cubic root of 138745 is about 51.7693184038.

The spelling of 138745 in words is "one hundred thirty-eight thousand, seven hundred forty-five".