506561221 has 2 divisors, whose sum is σ = 506561222. Its totient is φ = 506561220.

The previous prime is 506561179. The next prime is 506561233. The reversal of 506561221 is 122165605.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 317196100 + 189365121 = 17810^2 + 13761^2 .

It is a cyclic number.

It is not a de Polignac number, because 506561221 - 2¹¹ = 506559173 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 506561221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (506561021) 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, 253280610 + 253280611.

It is an arithmetic number, because the mean of its divisors is an integer number (253280611).

Almost surely, 2^506561221 is an apocalyptic number.

It is an amenable number.

506561221 is a deficient number, since it is larger than the sum of its proper divisors (1).

506561221 is an equidigital number, since it uses as much as digits as its factorization.

506561221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3600, while the sum is 28.

The square root of 506561221 is about 22506.9149596296. The cubic root of 506561221 is about 797.1572127707.

The spelling of 506561221 in words is "five hundred six million, five hundred sixty-one thousand, two hundred twenty-one".