56730221 has 2 divisors, whose sum is σ = 56730222. Its totient is φ = 56730220.

The previous prime is 56730203. The next prime is 56730229. The reversal of 56730221 is 12203765.

56730221 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., 29052100 + 27678121 = 5390^2 + 5261^2 .

It is a cyclic number.

It is not a de Polignac number, because 56730221 - 2¹⁸ = 56468077 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56730229) 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, 28365110 + 28365111.

It is an arithmetic number, because the mean of its divisors is an integer number (28365111).

Almost surely, 2^56730221 is an apocalyptic number.

It is an amenable number.

56730221 is a deficient number, since it is larger than the sum of its proper divisors (1).

56730221 is an equidigital number, since it uses as much as digits as its factorization.

56730221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 26.

The square root of 56730221 is about 7531.9466939165. The cubic root of 56730221 is about 384.2419920169.

Adding to 56730221 its reverse (12203765), we get a palindrome (68933986).

The spelling of 56730221 in words is "fifty-six million, seven hundred thirty thousand, two hundred twenty-one".