204580721 has 2 divisors, whose sum is σ = 204580722. Its totient is φ = 204580720.

The previous prime is 204580667. The next prime is 204580723. The reversal of 204580721 is 127085402.

204580721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138321121 + 66259600 = 11761^2 + 8140^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-204580721 is a prime.

It is a Sophie Germain prime.

Together with 204580723, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (204580723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102290360 + 102290361.

It is an arithmetic number, because the mean of its divisors is an integer number (102290361).

Almost surely, 2^204580721 is an apocalyptic number.

It is an amenable number.

204580721 is a deficient number, since it is larger than the sum of its proper divisors (1).

204580721 is an equidigital number, since it uses as much as digits as its factorization.

204580721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4480, while the sum is 29.

The square root of 204580721 is about 14303.1717111975. The cubic root of 204580721 is about 589.2345920666.

The spelling of 204580721 in words is "two hundred four million, five hundred eighty thousand, seven hundred twenty-one".