30736721 has 2 divisors, whose sum is σ = 30736722. Its totient is φ = 30736720.

The previous prime is 30736711. The next prime is 30736729. The reversal of 30736721 is 12763703.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 30195025 + 541696 = 5495^2 + 736^2 .

It is an emirp because it is prime and its reverse (12763703) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-30736721 is a prime.

It is a pancake number, because a pancake can be divided into 30736721 parts by 7840 straight cuts.

It is not a weakly prime, because it can be changed into another prime (30736729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15368360 + 15368361.

It is an arithmetic number, because the mean of its divisors is an integer number (15368361).

Almost surely, 2^30736721 is an apocalyptic number.

It is an amenable number.

30736721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30736721 is an equidigital number, since it uses as much as digits as its factorization.

30736721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5292, while the sum is 29.

The square root of 30736721 is about 5544.0707968063. The cubic root of 30736721 is about 313.2462243392.

The spelling of 30736721 in words is "thirty million, seven hundred thirty-six thousand, seven hundred twenty-one".