212221181 has 2 divisors, whose sum is σ = 212221182. Its totient is φ = 212221180.

The previous prime is 212221157. The next prime is 212221223. The reversal of 212221181 is 181122212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136095556 + 76125625 = 11666^2 + 8725^2 .

It is a cyclic number.

It is not a de Polignac number, because 212221181 - 2¹⁰ = 212220157 is a prime.

It is a super-2 number, since 2×212221181² = 90075659330069522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212229181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106110590 + 106110591.

It is an arithmetic number, because the mean of its divisors is an integer number (106110591).

Almost surely, 2^212221181 is an apocalyptic number.

It is an amenable number.

212221181 is a deficient number, since it is larger than the sum of its proper divisors (1).

212221181 is an equidigital number, since it uses as much as digits as its factorization.

212221181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 128, while the sum is 20.

The square root of 212221181 is about 14567.8131852382. The cubic root of 212221181 is about 596.4804889552.

Adding to 212221181 its reverse (181122212), we get a palindrome (393343393).

The spelling of 212221181 in words is "two hundred twelve million, two hundred twenty-one thousand, one hundred eighty-one".