306801221 has 2 divisors, whose sum is σ = 306801222. Its totient is φ = 306801220.

The previous prime is 306801197. The next prime is 306801223. The reversal of 306801221 is 122108603.

306801221 = 12385² + 12386².

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153412996 + 153388225 = 12386^2 + 12385^2 .

It is a cyclic number.

It is not a de Polignac number, because 306801221 - 2²² = 302606917 is a prime.

It is a Sophie Germain prime.

Together with 306801223, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (306801223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 153400610 + 153400611.

It is an arithmetic number, because the mean of its divisors is an integer number (153400611).

Almost surely, 2^306801221 is an apocalyptic number.

306801221 is the 12386-th centered square number.

It is an amenable number.

306801221 is a deficient number, since it is larger than the sum of its proper divisors (1).

306801221 is an equidigital number, since it uses as much as digits as its factorization.

306801221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 306801221 is about 17515.7420910448. The cubic root of 306801221 is about 674.4540412027.

Adding to 306801221 its reverse (122108603), we get a palindrome (428909824).

The spelling of 306801221 in words is "three hundred six million, eight hundred one thousand, two hundred twenty-one".