220776221 has 2 divisors, whose sum is σ = 220776222. Its totient is φ = 220776220.

The previous prime is 220776211. The next prime is 220776223. The reversal of 220776221 is 122677022.

220776221 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., 118483225 + 102292996 = 10885^2 + 10114^2 .

It is a cyclic number.

It is not a de Polignac number, because 220776221 - 2¹⁰ = 220775197 is a prime.

It is a Sophie Germain prime.

Together with 220776223, it forms a pair of twin primes.

It is a Chen 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 (220776223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110388110 + 110388111.

It is an arithmetic number, because the mean of its divisors is an integer number (110388111).

Almost surely, 2^220776221 is an apocalyptic number.

It is an amenable number.

220776221 is a deficient number, since it is larger than the sum of its proper divisors (1).

220776221 is an equidigital number, since it uses as much as digits as its factorization.

220776221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 220776221 is about 14858.5403388085. The cubic root of 220776221 is about 604.3902250424.

The spelling of 220776221 in words is "two hundred twenty million, seven hundred seventy-six thousand, two hundred twenty-one".