21022010209 has 2 divisors, whose sum is σ = 21022010210. Its totient is φ = 21022010208.

The previous prime is 21022010201. The next prime is 21022010213. The reversal of 21022010209 is 90201022012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12316560400 + 8705449809 = 110980^2 + 93303^2 .

It is a cyclic number.

It is not a de Polignac number, because 21022010209 - 2³ = 21022010201 is a prime.

It is a super-3 number, since 3×21022010209³ (a number of 32 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (21022010201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10511005104 + 10511005105.

It is an arithmetic number, because the mean of its divisors is an integer number (10511005105).

Almost surely, 2^21022010209 is an apocalyptic number.

It is an amenable number.

21022010209 is a deficient number, since it is larger than the sum of its proper divisors (1).

21022010209 is an equidigital number, since it uses as much as digits as its factorization.

21022010209 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 19.

The spelling of 21022010209 in words is "twenty-one billion, twenty-two million, ten thousand, two hundred nine".