212122121 has 2 divisors, whose sum is σ = 212122122. Its totient is φ = 212122120.

The previous prime is 212122109. The next prime is 212122129. The reversal of 212122121 is 121221212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211382521 + 739600 = 14539^2 + 860^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-212122121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 212122096 and 212122105.

It is not a weakly prime, because it can be changed into another prime (212122129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106061060 + 106061061.

It is an arithmetic number, because the mean of its divisors is an integer number (106061061).

Almost surely, 2^212122121 is an apocalyptic number.

It is an amenable number.

212122121 is a deficient number, since it is larger than the sum of its proper divisors (1).

212122121 is an equidigital number, since it uses as much as digits as its factorization.

212122121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32, while the sum is 14.

The square root of 212122121 is about 14564.4128271620. The cubic root of 212122121 is about 596.3876666886.

Adding to 212122121 its reverse (121221212), we get a palindrome (333343333).

Subtracting from 212122121 its reverse (121221212), we obtain a palindrome (90900909).

It can be divided in two parts, 2121 and 22121, that added together give a palindrome (24242).

The spelling of 212122121 in words is "two hundred twelve million, one hundred twenty-two thousand, one hundred twenty-one".