205550221 has 2 divisors, whose sum is σ = 205550222. Its totient is φ = 205550220.

The previous prime is 205550197. The next prime is 205550237. The reversal of 205550221 is 122055502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166048996 + 39501225 = 12886^2 + 6285^2 .

It is a cyclic number.

It is not a de Polignac number, because 205550221 - 2²¹ = 203453069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 205550192 and 205550201.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (205553221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 102775110 + 102775111.

It is an arithmetic number, because the mean of its divisors is an integer number (102775111).

Almost surely, 2^205550221 is an apocalyptic number.

It is an amenable number.

205550221 is a deficient number, since it is larger than the sum of its proper divisors (1).

205550221 is an equidigital number, since it uses as much as digits as its factorization.

205550221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1000, while the sum is 22.

The square root of 205550221 is about 14337.0227383512. The cubic root of 205550221 is about 590.1639121332.

The spelling of 205550221 in words is "two hundred five million, five hundred fifty thousand, two hundred twenty-one".