21211222189 has 2 divisors, whose sum is σ = 21211222190. Its totient is φ = 21211222188.

The previous prime is 21211222183. The next prime is 21211222217. The reversal of 21211222189 is 98122211212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17764358089 + 3446864100 = 133283^2 + 58710^2 .

It is a cyclic number.

It is not a de Polignac number, because 21211222189 - 2³ = 21211222181 is a prime.

It is a super-2 number, since 2×21211222189² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21211222189.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21211222181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605611094 + 10605611095.

It is an arithmetic number, because the mean of its divisors is an integer number (10605611095).

Almost surely, 2^21211222189 is an apocalyptic number.

It is an amenable number.

21211222189 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211222189 is an equidigital number, since it uses as much as digits as its factorization.

21211222189 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2304, while the sum is 31.

The spelling of 21211222189 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-two thousand, one hundred eighty-nine".