22102121221 has 2 divisors, whose sum is σ = 22102121222. Its totient is φ = 22102121220.

The previous prime is 22102121213. The next prime is 22102121233. The reversal of 22102121221 is 12212120122.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14133880996 + 7968240225 = 118886^2 + 89265^2 .

It is a cyclic number.

It is not a de Polignac number, because 22102121221 - 2³ = 22102121213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 22102121195 and 22102121204.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (22102121201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11051060610 + 11051060611.

It is an arithmetic number, because the mean of its divisors is an integer number (11051060611).

Almost surely, 2^22102121221 is an apocalyptic number.

It is an amenable number.

22102121221 is a deficient number, since it is larger than the sum of its proper divisors (1).

22102121221 is an equidigital number, since it uses as much as digits as its factorization.

22102121221 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 22102121221 its reverse (12212120122), we get a palindrome (34314241343).

It can be divided in two parts, 221021 and 21221, that added together give a palindrome (242242).

The spelling of 22102121221 in words is "twenty-two billion, one hundred two million, one hundred twenty-one thousand, two hundred twenty-one".