312817 has 4 divisors (see below), whose sum is σ = 331236. Its totient is φ = 294400.

The previous prime is 312799. The next prime is 312839. The reversal of 312817 is 718213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 718213 = 139 ⋅5167.

It can be written as a sum of positive squares in 2 ways, for example, as 194481 + 118336 = 441^2 + 344^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-312817 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

312817 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (312857) 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, 9184 + ... + 9217.

It is an arithmetic number, because the mean of its divisors is an integer number (82809).

2³¹²⁸¹⁷ is an apocalyptic number.

It is an amenable number.

312817 is a deficient number, since it is larger than the sum of its proper divisors (18419).

312817 is a wasteful number, since it uses less digits than its factorization.

312817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18418.

The product of its digits is 336, while the sum is 22.

The square root of 312817 is about 559.3004559269. The cubic root of 312817 is about 67.8833785374.

Subtracting from 312817 its product of digits (336), we obtain a square (312481 = 559²).

The spelling of 312817 in words is "three hundred twelve thousand, eight hundred seventeen".