212242242221 has 2 divisors, whose sum is σ = 212242242222. Its totient is φ = 212242242220.

The previous prime is 212242242217. The next prime is 212242242307. The reversal of 212242242221 is 122242242212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 211719616900 + 522625321 = 460130^2 + 22861^2 .

It is a cyclic number.

It is not a de Polignac number, because 212242242221 - 2² = 212242242217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212242242521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106121121110 + 106121121111.

It is an arithmetic number, because the mean of its divisors is an integer number (106121121111).

Almost surely, 2^212242242221 is an apocalyptic number.

It is an amenable number.

212242242221 is a deficient number, since it is larger than the sum of its proper divisors (1).

212242242221 is an equidigital number, since it uses as much as digits as its factorization.

212242242221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4096, while the sum is 26.

Adding to 212242242221 its reverse (122242242212), we get a palindrome (334484484433).

Subtracting from 212242242221 its reverse (122242242212), we obtain a palindrome (90000000009).

The spelling of 212242242221 in words is "two hundred twelve billion, two hundred forty-two million, two hundred forty-two thousand, two hundred twenty-one".