312021 has 12 divisors (see below), whose sum is σ = 463372. Its totient is φ = 202176.

The previous prime is 312007. The next prime is 312023. The reversal of 312021 is 120213.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 140625 + 171396 = 375^2 + 414^2 .

It is not a de Polignac number, because 312021 - 2⁶ = 311957 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

312021 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 311994 and 312012.

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 312021.

It is not an unprimeable number, because it can be changed into a prime (312023) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136 + ... + 801.

2³¹²⁰²¹ is an apocalyptic number.

It is an amenable number.

312021 is a deficient number, since it is larger than the sum of its proper divisors (151351).

312021 is a wasteful number, since it uses less digits than its factorization.

312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 980 (or 977 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 312021 is about 558.5883994499. The cubic root of 312021 is about 67.8257505236.

Adding to 312021 its reverse (120213), we get a palindrome (432234).

It can be divided in two parts, 3 and 12021, that multiplied together give a palindrome (36063).

The spelling of 312021 in words is "three hundred twelve thousand, twenty-one", and thus it is an iban number.