21220221120209 has 2 divisors, whose sum is σ = 21220221120210. Its totient is φ = 21220221120208.

The previous prime is 21220221120187. The next prime is 21220221120253. The reversal of 21220221120209 is 90202112202212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11897256577600 + 9322964542609 = 3449240^2 + 3053353^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220221120209 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220221120289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610110560104 + 10610110560105.

It is an arithmetic number, because the mean of its divisors is an integer number (10610110560105).

Almost surely, 2^{21220221120209} is an apocalyptic number.

It is an amenable number.

21220221120209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220221120209 is an equidigital number, since it uses as much as digits as its factorization.

21220221120209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 26.

The spelling of 21220221120209 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty-one million, one hundred twenty thousand, two hundred nine".