21222112120021 has 2 divisors, whose sum is σ = 21222112120022. Its totient is φ = 21222112120020.

The previous prime is 21222112119947. The next prime is 21222112120051. The reversal of 21222112120021 is 12002121122212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14018202439921 + 7203909680100 = 3744089^2 + 2684010^2 .

It is a cyclic number.

It is not a de Polignac number, because 21222112120021 - 2³¹ = 21219964636373 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21222112120051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611056060010 + 10611056060011.

It is an arithmetic number, because the mean of its divisors is an integer number (10611056060011).

Almost surely, 2^{21222112120021} is an apocalyptic number.

It is an amenable number.

21222112120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

21222112120021 is an equidigital number, since it uses as much as digits as its factorization.

21222112120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21222112120021 its reverse (12002121122212), we get a palindrome (33224233242233).

The spelling of 21222112120021 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twelve million, one hundred twenty thousand, twenty-one".