221020211 has 2 divisors, whose sum is σ = 221020212. Its totient is φ = 221020210.

The previous prime is 221020207. The next prime is 221020237. The reversal of 221020211 is 112020122.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221020211 - 2² = 221020207 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221020192 and 221020201.

It is not a weakly prime, because it can be changed into another prime (221020511) 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, 110510105 + 110510106.

It is an arithmetic number, because the mean of its divisors is an integer number (110510106).

Almost surely, 2^221020211 is an apocalyptic number.

221020211 is a deficient number, since it is larger than the sum of its proper divisors (1).

221020211 is an equidigital number, since it uses as much as digits as its factorization.

221020211 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 221020211 is about 14866.7485012695. The cubic root of 221020211 is about 604.6127895924.

Adding to 221020211 its reverse (112020122), we get a palindrome (333040333).

The spelling of 221020211 in words is "two hundred twenty-one million, twenty thousand, two hundred eleven".