306106721 has 2 divisors, whose sum is σ = 306106722. Its totient is φ = 306106720.

The previous prime is 306106711. The next prime is 306106763. The reversal of 306106721 is 127601603.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 293779600 + 12327121 = 17140^2 + 3511^2 .

It is an emirp because it is prime and its reverse (127601603) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 306106721 - 2¹⁰ = 306105697 is a prime.

It is not a weakly prime, because it can be changed into another prime (306106711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 153053360 + 153053361.

It is an arithmetic number, because the mean of its divisors is an integer number (153053361).

Almost surely, 2^306106721 is an apocalyptic number.

It is an amenable number.

306106721 is a deficient number, since it is larger than the sum of its proper divisors (1).

306106721 is an equidigital number, since it uses as much as digits as its factorization.

306106721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1512, while the sum is 26.

The square root of 306106721 is about 17495.9058353662. The cubic root of 306106721 is about 673.9447405144.

The spelling of 306106721 in words is "three hundred six million, one hundred six thousand, seven hundred twenty-one".