139505 has 4 divisors (see below), whose sum is σ = 167412. Its totient is φ = 111600.

The previous prime is 139501. The next prime is 139511. The reversal of 139505 is 505931.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 505931 = 23 ⋅21997.

It can be written as a sum of positive squares in 2 ways, for example, as 92416 + 47089 = 304^2 + 217^2 .

It is not a de Polignac number, because 139505 - 2² = 139501 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139501) 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 in 3 ways as a sum of consecutive naturals, for example, 13946 + ... + 13955.

It is an arithmetic number, because the mean of its divisors is an integer number (41853).

2¹³⁹⁵⁰⁵ is an apocalyptic number.

It is an amenable number.

139505 is a deficient number, since it is larger than the sum of its proper divisors (27907).

139505 is an equidigital number, since it uses as much as digits as its factorization.

139505 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27906.

The product of its (nonzero) digits is 675, while the sum is 23.

The square root of 139505 is about 373.5036813741. The cubic root of 139505 is about 51.8636714993.

The spelling of 139505 in words is "one hundred thirty-nine thousand, five hundred five".