313821 has 16 divisors (see below), whose sum is σ = 475200. Its totient is φ = 204624.

The previous prime is 313783. The next prime is 313829. The reversal of 313821 is 128313.

It is not a de Polignac number, because 313821 - 2¹⁵ = 281053 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 313794 and 313803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1495 + ... + 1691.

It is an arithmetic number, because the mean of its divisors is an integer number (29700).

2³¹³⁸²¹ is an apocalyptic number.

It is an amenable number.

313821 is a deficient number, since it is larger than the sum of its proper divisors (161379).

313821 is a wasteful number, since it uses less digits than its factorization.

313821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 265 (or 259 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 313821 is about 560.1972866768. The cubic root of 313821 is about 67.9559258802.

It can be divided in two parts, 3 and 13821, that added together give a cube (13824 = 24³).

The spelling of 313821 in words is "three hundred thirteen thousand, eight hundred twenty-one".