21021102211121 has 2 divisors, whose sum is σ = 21021102211122. Its totient is φ = 21021102211120.

The previous prime is 21021102211099. The next prime is 21021102211211. The reversal of 21021102211121 is 12111220112012.

Together with next prime (21021102211211) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20335013038096 + 686089173025 = 4509436^2 + 828305^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021102211121 - 2²² = 21021098016817 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21021102211121.

It is not a weakly prime, because it can be changed into another prime (21021102231121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510551105560 + 10510551105561.

It is an arithmetic number, because the mean of its divisors is an integer number (10510551105561).

Almost surely, 2^{21021102211121} is an apocalyptic number.

It is an amenable number.

21021102211121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021102211121 is an equidigital number, since it uses as much as digits as its factorization.

21021102211121 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 21021102211121 its reverse (12111220112012), we get a palindrome (33132322323133).

The spelling of 21021102211121 in words is "twenty-one trillion, twenty-one billion, one hundred two million, two hundred eleven thousand, one hundred twenty-one".