313211221 has 4 divisors (see below), whose sum is σ = 317176000. Its totient is φ = 309246444.

The previous prime is 313211209. The next prime is 313211251. The reversal of 313211221 is 122112313.

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 313211221 - 2¹⁷ = 313080149 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 313211195 and 313211204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313211251) 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, 1982271 + ... + 1982428.

It is an arithmetic number, because the mean of its divisors is an integer number (79294000).

Almost surely, 2^313211221 is an apocalyptic number.

It is an amenable number.

313211221 is a deficient number, since it is larger than the sum of its proper divisors (3964779).

313211221 is an equidigital number, since it uses as much as digits as its factorization.

313211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3964778.

The product of its digits is 72, while the sum is 16.

The square root of 313211221 is about 17697.7744646043. The cubic root of 313211221 is about 679.1188276356.

Adding to 313211221 its reverse (122112313), we get a palindrome (435323534).

The spelling of 313211221 in words is "three hundred thirteen million, two hundred eleven thousand, two hundred twenty-one".