306343721 has 2 divisors, whose sum is σ = 306343722. Its totient is φ = 306343720.

The previous prime is 306343711. The next prime is 306343789. The reversal of 306343721 is 127343603.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 284394496 + 21949225 = 16864^2 + 4685^2 .

It is a cyclic number.

It is not a de Polignac number, because 306343721 - 2¹⁰ = 306342697 is a prime.

It is a super-2 number, since 2×306343721² = 187692950792251682, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (306343711) 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, 153171860 + 153171861.

It is an arithmetic number, because the mean of its divisors is an integer number (153171861).

Almost surely, 2^306343721 is an apocalyptic number.

It is an amenable number.

306343721 is a deficient number, since it is larger than the sum of its proper divisors (1).

306343721 is an equidigital number, since it uses as much as digits as its factorization.

306343721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 29.

The square root of 306343721 is about 17502.6775380226. The cubic root of 306343721 is about 674.1186272544.

The spelling of 306343721 in words is "three hundred six million, three hundred forty-three thousand, seven hundred twenty-one".