21221121102121 has 2 divisors, whose sum is σ = 21221121102122. Its totient is φ = 21221121102120.

The previous prime is 21221121102113. The next prime is 21221121102157. The reversal of 21221121102121 is 12120112112212.

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., 11116122787225 + 10104998314896 = 3334085^2 + 3178836^2 .

It is a cyclic number.

It is not a de Polignac number, because 21221121102121 - 2³ = 21221121102113 is a prime.

It is not a weakly prime, because it can be changed into another prime (21221121102161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610560551060 + 10610560551061.

It is an arithmetic number, because the mean of its divisors is an integer number (10610560551061).

Almost surely, 2^{21221121102121} is an apocalyptic number.

It is an amenable number.

21221121102121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221121102121 is an equidigital number, since it uses as much as digits as its factorization.

21221121102121 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 21221121102121 its reverse (12120112112212), we get a palindrome (33341233214333).

The spelling of 21221121102121 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-one million, one hundred two thousand, one hundred twenty-one".