312881 has 4 divisors (see below), whose sum is σ = 323700. Its totient is φ = 302064.

The previous prime is 312863. The next prime is 312887. The reversal of 312881 is 188213.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 188213 = 107 ⋅1759.

It can be written as a sum of positive squares in 2 ways, for example, as 152881 + 160000 = 391^2 + 400^2 .

It is a de Polignac number, because none of the positive numbers 2^k-312881 is a prime.

It is a super-2 number, since 2×312881² = 195789040322, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 312881.

It is not an unprimeable number, because it can be changed into a prime (312887) 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, 5366 + ... + 5423.

It is an arithmetic number, because the mean of its divisors is an integer number (80925).

2³¹²⁸⁸¹ is an apocalyptic number.

It is an amenable number.

312881 is a deficient number, since it is larger than the sum of its proper divisors (10819).

312881 is a wasteful number, since it uses less digits than its factorization.

312881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10818.

The product of its digits is 384, while the sum is 23.

The square root of 312881 is about 559.3576673292. The cubic root of 312881 is about 67.8880076975. Note that the first 3 decimals are identical.

The spelling of 312881 in words is "three hundred twelve thousand, eight hundred eighty-one".