206222021 has 2 divisors, whose sum is σ = 206222022. Its totient is φ = 206222020.

The previous prime is 206221973. The next prime is 206222039. The reversal of 206222021 is 120222602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 176092900 + 30129121 = 13270^2 + 5489^2 .

It is a cyclic number.

It is not a de Polignac number, because 206222021 - 2⁶ = 206221957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (206222321) 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, 103111010 + 103111011.

It is an arithmetic number, because the mean of its divisors is an integer number (103111011).

Almost surely, 2^206222021 is an apocalyptic number.

It is an amenable number.

206222021 is a deficient number, since it is larger than the sum of its proper divisors (1).

206222021 is an equidigital number, since it uses as much as digits as its factorization.

206222021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 206222021 is about 14360.4324795599. The cubic root of 206222021 is about 590.8061573985.

Adding to 206222021 its reverse (120222602), we get a palindrome (326444623).

The spelling of 206222021 in words is "two hundred six million, two hundred twenty-two thousand, twenty-one".