30306721 has 2 divisors, whose sum is σ = 30306722. Its totient is φ = 30306720.

The previous prime is 30306697. The next prime is 30306761. The reversal of 30306721 is 12760303.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 29430625 + 876096 = 5425^2 + 936^2 .

It is a cyclic number.

It is not a de Polignac number, because 30306721 - 2⁷ = 30306593 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 30306692 and 30306701.

It is not a weakly prime, because it can be changed into another prime (30306761) 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, 15153360 + 15153361.

It is an arithmetic number, because the mean of its divisors is an integer number (15153361).

Almost surely, 2^30306721 is an apocalyptic number.

It is an amenable number.

30306721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30306721 is an equidigital number, since it uses as much as digits as its factorization.

30306721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 756, while the sum is 22.

The square root of 30306721 is about 5505.1540396250. The cubic root of 30306721 is about 311.7786103383.

The spelling of 30306721 in words is "thirty million, three hundred six thousand, seven hundred twenty-one".