21220010202121 has 2 divisors, whose sum is σ = 21220010202122. Its totient is φ = 21220010202120.

The previous prime is 21220010202073. The next prime is 21220010202137. The reversal of 21220010202121 is 12120201002212.

It is a happy number.

It is an a-pointer prime, because the next prime (21220010202137) can be obtained adding 21220010202121 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11364052265721 + 9855957936400 = 3371061^2 + 3139420^2 .

It is a cyclic number.

It is not a de Polignac number, because 21220010202121 - 2²¹ = 21220008104969 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21220010202095 and 21220010202104.

It is not a weakly prime, because it can be changed into another prime (21220010202421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610005101060 + 10610005101061.

It is an arithmetic number, because the mean of its divisors is an integer number (10610005101061).

Almost surely, 2^{21220010202121} is an apocalyptic number.

It is an amenable number.

21220010202121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220010202121 is an equidigital number, since it uses as much as digits as its factorization.

21220010202121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21220010202121 its reverse (12120201002212), we get a palindrome (33340211204333).

The spelling of 21220010202121 in words is "twenty-one trillion, two hundred twenty billion, ten million, two hundred two thousand, one hundred twenty-one".