212221321309 has 2 divisors, whose sum is σ = 212221321310. Its totient is φ = 212221321308.

The previous prime is 212221321307. The next prime is 212221321321. The reversal of 212221321309 is 903123122212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 204747200100 + 7474121209 = 452490^2 + 86453^2 .

It is a cyclic number.

It is not a de Polignac number, because 212221321309 - 2¹ = 212221321307 is a prime.

Together with 212221321307, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (212221321303) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 106110660654 + 106110660655.

It is an arithmetic number, because the mean of its divisors is an integer number (106110660655).

Almost surely, 2^212221321309 is an apocalyptic number.

It is an amenable number.

212221321309 is a deficient number, since it is larger than the sum of its proper divisors (1).

212221321309 is an equidigital number, since it uses as much as digits as its factorization.

212221321309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 212221321309 in words is "two hundred twelve billion, two hundred twenty-one million, three hundred twenty-one thousand, three hundred nine".