137509 has 4 divisors (see below), whose sum is σ = 138400. Its totient is φ = 136620.

The previous prime is 137507. The next prime is 137519. The reversal of 137509 is 905731.

137509 is nontrivially palindromic in base 11.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 905731 = 41 ⋅22091.

It is a cyclic number.

It is not a de Polignac number, because 137509 - 2¹ = 137507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (137507) 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, 147 + ... + 544.

It is an arithmetic number, because the mean of its divisors is an integer number (34600).

2¹³⁷⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

137509 is a deficient number, since it is larger than the sum of its proper divisors (891).

137509 is an equidigital number, since it uses as much as digits as its factorization.

137509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 890.

The product of its (nonzero) digits is 945, while the sum is 25.

The square root of 137509 is about 370.8220597537. The cubic root of 137509 is about 51.6151318720.

It can be divided in two parts, 137 and 509, that added together give a palindrome (646).

The spelling of 137509 in words is "one hundred thirty-seven thousand, five hundred nine".