212120221 has 2 divisors, whose sum is σ = 212120222. Its totient is φ = 212120220.

The previous prime is 212120201. The next prime is 212120231. The reversal of 212120221 is 122021212.

It is a happy number.

212120221 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., 131928196 + 80192025 = 11486^2 + 8955^2 .

It is a cyclic number.

It is not a de Polignac number, because 212120221 - 2⁵ = 212120189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212120201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060110 + 106060111.

It is an arithmetic number, because the mean of its divisors is an integer number (106060111).

Almost surely, 2^212120221 is an apocalyptic number.

It is an amenable number.

212120221 is a deficient number, since it is larger than the sum of its proper divisors (1).

212120221 is an equidigital number, since it uses as much as digits as its factorization.

212120221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 212120221 is about 14564.3475995322. The cubic root of 212120221 is about 596.3858860477.

Adding to 212120221 its reverse (122021212), we get a palindrome (334141433).

Subtracting from 212120221 its reverse (122021212), we obtain a palindrome (90099009).

The spelling of 212120221 in words is "two hundred twelve million, one hundred twenty thousand, two hundred twenty-one".