2121011112221 has 2 divisors, whose sum is σ = 2121011112222. Its totient is φ = 2121011112220.

The previous prime is 2121011112203. The next prime is 2121011112271. The reversal of 2121011112221 is 1222111101212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1707754989721 + 413256122500 = 1306811^2 + 642850^2 .

It is a cyclic number.

It is not a de Polignac number, because 2121011112221 - 2²⁶ = 2120944003357 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2121011112221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2121011112271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1060505556110 + 1060505556111.

It is an arithmetic number, because the mean of its divisors is an integer number (1060505556111).

Almost surely, 2^{2121011112221} is an apocalyptic number.

It is an amenable number.

2121011112221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2121011112221 is an equidigital number, since it uses as much as digits as its factorization.

2121011112221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 2121011112221 its reverse (1222111101212), we get a palindrome (3343122213433).

The spelling of 2121011112221 in words is "two trillion, one hundred twenty-one billion, eleven million, one hundred twelve thousand, two hundred twenty-one".