313221221 has 4 divisors (see below), whose sum is σ = 313298412. Its totient is φ = 313144032.

The previous prime is 313221203. The next prime is 313221253. The reversal of 313221221 is 122122313.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 122122313 = 41 ⋅2978593.

It can be written as a sum of positive squares in 2 ways, for example, as 65788321 + 247432900 = 8111^2 + 15730^2 .

It is a cyclic number.

It is not a de Polignac number, because 313221221 - 2⁶ = 313221157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 313221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (313221281) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32150 + ... + 40743.

It is an arithmetic number, because the mean of its divisors is an integer number (78324603).

Almost surely, 2^313221221 is an apocalyptic number.

It is an amenable number.

313221221 is a deficient number, since it is larger than the sum of its proper divisors (77191).

313221221 is an equidigital number, since it uses as much as digits as its factorization.

313221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77190.

The product of its digits is 144, while the sum is 17.

The square root of 313221221 is about 17698.0569837482. The cubic root of 313221221 is about 679.1260550438.

Adding to 313221221 its reverse (122122313), we get a palindrome (435343534).

The spelling of 313221221 in words is "three hundred thirteen million, two hundred twenty-one thousand, two hundred twenty-one".