313220021 has 2 divisors, whose sum is σ = 313220022. Its totient is φ = 313220020.

The previous prime is 313220009. The next prime is 313220027. The reversal of 313220021 is 120022313.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171348100 + 141871921 = 13090^2 + 11911^2 .

It is an emirp because it is prime and its reverse (120022313) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-313220021 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 313219978 and 313220005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (313220027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 156610010 + 156610011.

It is an arithmetic number, because the mean of its divisors is an integer number (156610011).

Almost surely, 2^313220021 is an apocalyptic number.

It is an amenable number.

313220021 is a deficient number, since it is larger than the sum of its proper divisors (1).

313220021 is an equidigital number, since it uses as much as digits as its factorization.

313220021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 313220021 is about 17698.0230816891. The cubic root of 313220021 is about 679.1251877629.

Adding to 313220021 its reverse (120022313), we get a palindrome (433242334).

The spelling of 313220021 in words is "three hundred thirteen million, two hundred twenty thousand, twenty-one".