312009 has 4 divisors (see below), whose sum is σ = 416016. Its totient is φ = 208004.

The previous prime is 312007. The next prime is 312023. The reversal of 312009 is 900213.

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 312009 - 2¹ = 312007 is a prime.

It is a D-number.

It is not an unprimeable number, because it can be changed into a prime (312007) 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, 51999 + ... + 52004.

It is an arithmetic number, because the mean of its divisors is an integer number (104004).

2³¹²⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

312009 is a deficient number, since it is larger than the sum of its proper divisors (104007).

312009 is a wasteful number, since it uses less digits than its factorization.

312009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104006.

The product of its (nonzero) digits is 54, while the sum is 15.

The square root of 312009 is about 558.5776579850. The cubic root of 312009 is about 67.8248810101.

The spelling of 312009 in words is "three hundred twelve thousand, nine".