316220921 has 2 divisors, whose sum is σ = 316220922. Its totient is φ = 316220920.

The previous prime is 316220911. The next prime is 316220929. The reversal of 316220921 is 129022613.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 308178025 + 8042896 = 17555^2 + 2836^2 .

It is a cyclic number.

It is not a de Polignac number, because 316220921 - 2¹⁸ = 315958777 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (316220929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 158110460 + 158110461.

It is an arithmetic number, because the mean of its divisors is an integer number (158110461).

Almost surely, 2^316220921 is an apocalyptic number.

It is an amenable number.

316220921 is a deficient number, since it is larger than the sum of its proper divisors (1).

316220921 is an equidigital number, since it uses as much as digits as its factorization.

316220921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 316220921 is about 17782.6016375557. The cubic root of 316220921 is about 681.2871533086.

The spelling of 316220921 in words is "three hundred sixteen million, two hundred twenty thousand, nine hundred twenty-one".