312509 has 2 divisors, whose sum is σ = 312510. Its totient is φ = 312508.

The previous prime is 312469. The next prime is 312517. The reversal of 312509 is 905213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 235225 + 77284 = 485^2 + 278^2 .

It is an emirp because it is prime and its reverse (905213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 312509 - 2⁸ = 312253 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 312509.

It is not a weakly prime, because it can be changed into another prime (312589) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156254 + 156255.

It is an arithmetic number, because the mean of its divisors is an integer number (156255).

2³¹²⁵⁰⁹ is an apocalyptic number.

It is an amenable number.

312509 is a deficient number, since it is larger than the sum of its proper divisors (1).

312509 is an equidigital number, since it uses as much as digits as its factorization.

312509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 270, while the sum is 20.

The square root of 312509 is about 559.0250441617. The cubic root of 312509 is about 67.8610918688.

Subtracting 312509 from its reverse (905213), we obtain a cube (592704 = 84³).

The spelling of 312509 in words is "three hundred twelve thousand, five hundred nine".