212121101022121 has 2 divisors, whose sum is σ = 212121101022122. Its totient is φ = 212121101022120.

The previous prime is 212121101022109. The next prime is 212121101022151. The reversal of 212121101022121 is 121220101121212.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 191037621716496 + 21083479305625 = 13821636^2 + 4591675^2 .

It is a cyclic number.

It is not a de Polignac number, because 212121101022121 - 2⁷ = 212121101021993 is a prime.

It is a super-3 number, since 3×212121101022121³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (212121101022151) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106060550511060 + 106060550511061.

It is an arithmetic number, because the mean of its divisors is an integer number (106060550511061).

Almost surely, 2^{212121101022121} is an apocalyptic number.

It is an amenable number.

212121101022121 is a deficient number, since it is larger than the sum of its proper divisors (1).

212121101022121 is an equidigital number, since it uses as much as digits as its factorization.

212121101022121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 212121101022121 its reverse (121220101121212), we get a palindrome (333341202143333).

Subtracting from 212121101022121 its reverse (121220101121212), we obtain a palindrome (90900999900909).

The spelling of 212121101022121 in words is "two hundred twelve trillion, one hundred twenty-one billion, one hundred one million, twenty-two thousand, one hundred twenty-one".