12731509 has 4 divisors (see below), whose sum is σ = 14550304. Its totient is φ = 10912716.

The previous prime is 12731503. The next prime is 12731531. The reversal of 12731509 is 90513721.

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.

It is a cyclic number.

It is not a de Polignac number, because 12731509 - 2¹³ = 12723317 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 (12731503) 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, 909387 + ... + 909400.

It is an arithmetic number, because the mean of its divisors is an integer number (3637576).

Almost surely, 2^12731509 is an apocalyptic number.

It is an amenable number.

12731509 is a deficient number, since it is larger than the sum of its proper divisors (1818795).

12731509 is an equidigital number, since it uses as much as digits as its factorization.

12731509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1818794.

The product of its (nonzero) digits is 1890, while the sum is 28.

The square root of 12731509 is about 3568.1240169030. The cubic root of 12731509 is about 233.5034457901.

The spelling of 12731509 in words is "twelve million, seven hundred thirty-one thousand, five hundred nine".