21222121221277 has 2 divisors, whose sum is σ = 21222121221278. Its totient is φ = 21222121221276.

The previous prime is 21222121221227. The next prime is 21222121221307. The reversal of 21222121221277 is 77212212122212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20581882799076 + 640238422201 = 4536726^2 + 800149^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21222121221277 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222121221227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611060610638 + 10611060610639.

It is an arithmetic number, because the mean of its divisors is an integer number (10611060610639).

Almost surely, 2^{21222121221277} is an apocalyptic number.

It is an amenable number.

21222121221277 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222121221277 is an equidigital number, since it uses as much as digits as its factorization.

21222121221277 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12544, while the sum is 34.

Adding to 21222121221277 its reverse (77212212122212), we get a palindrome (98434333343489).

The spelling of 21222121221277 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred seventy-seven".