22122212121221 has 2 divisors, whose sum is σ = 22122212121222. Its totient is φ = 22122212121220.

The previous prime is 22122212121109. The next prime is 22122212121287. The reversal of 22122212121221 is 12212121222122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18521747616100 + 3600464505121 = 4303690^2 + 1897489^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-22122212121221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22122212120221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11061106060610 + 11061106060611.

It is an arithmetic number, because the mean of its divisors is an integer number (11061106060611).

Almost surely, 2^{22122212121221} is an apocalyptic number.

It is an amenable number.

22122212121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22122212121221 is an equidigital number, since it uses as much as digits as its factorization.

22122212121221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 512, while the sum is 23.

Adding to 22122212121221 its reverse (12212121222122), we get a palindrome (34334333343343).

The spelling of 22122212121221 in words is "twenty-two trillion, one hundred twenty-two billion, two hundred twelve million, one hundred twenty-one thousand, two hundred twenty-one".