306812021 has 2 divisors, whose sum is σ = 306812022. Its totient is φ = 306812020.

The previous prime is 306811987. The next prime is 306812041. The reversal of 306812021 is 120218603.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 217887121 + 88924900 = 14761^2 + 9430^2 .

It is an emirp because it is prime and its reverse (120218603) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 306812021 - 2¹⁰ = 306810997 is a prime.

It is a Chen prime.

It is equal to p_16601117 and since 306812021 and 16601117 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (306812041) 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 as a sum of consecutive naturals, namely, 153406010 + 153406011.

It is an arithmetic number, because the mean of its divisors is an integer number (153406011).

Almost surely, 2^306812021 is an apocalyptic number.

It is an amenable number.

306812021 is a deficient number, since it is larger than the sum of its proper divisors (1).

306812021 is an equidigital number, since it uses as much as digits as its factorization.

306812021 is an odious number, because the sum of its binary digits is odd.

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

The square root of 306812021 is about 17516.0503824350. The cubic root of 306812021 is about 674.4619551414.

The spelling of 306812021 in words is "three hundred six million, eight hundred twelve thousand, twenty-one".