30019721 has 2 divisors, whose sum is σ = 30019722. Its totient is φ = 30019720.

The previous prime is 30019711. The next prime is 30019733. The reversal of 30019721 is 12791003.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 22429696 + 7590025 = 4736^2 + 2755^2 .

It is a cyclic number.

It is not a de Polignac number, because 30019721 - 2¹⁸ = 29757577 is a prime.

It is not a weakly prime, because it can be changed into another prime (30019711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15009860 + 15009861.

It is an arithmetic number, because the mean of its divisors is an integer number (15009861).

Almost surely, 2^30019721 is an apocalyptic number.

It is an amenable number.

30019721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30019721 is an equidigital number, since it uses as much as digits as its factorization.

30019721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 378, while the sum is 23.

The square root of 30019721 is about 5479.0255520485. The cubic root of 30019721 is about 310.7913220508.

The spelling of 30019721 in words is "thirty million, nineteen thousand, seven hundred twenty-one".