138965 has 4 divisors (see below), whose sum is σ = 166764. Its totient is φ = 111168.

The previous prime is 138959. The next prime is 138967. The reversal of 138965 is 569831.

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 21316 + 117649 = 146^2 + 343^2 .

It is a cyclic number.

It is not a de Polignac number, because 138965 - 2¹⁰ = 137941 is a prime.

It is a super-2 number, since 2×138965² = 38622542450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138967) 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, 13892 + ... + 13901.

It is an arithmetic number, because the mean of its divisors is an integer number (41691).

2¹³⁸⁹⁶⁵ is an apocalyptic number.

It is an amenable number.

138965 is a deficient number, since it is larger than the sum of its proper divisors (27799).

138965 is an equidigital number, since it uses as much as digits as its factorization.

138965 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27798.

The product of its digits is 6480, while the sum is 32.

The square root of 138965 is about 372.7800960352. The cubic root of 138965 is about 51.7966665018.

The spelling of 138965 in words is "one hundred thirty-eight thousand, nine hundred sixty-five".