6221309 has 2 divisors, whose sum is σ = 6221310. Its totient is φ = 6221308.

The previous prime is 6221287. The next prime is 6221311. The reversal of 6221309 is 9031226.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6100900 + 120409 = 2470^2 + 347^2 .

It is a cyclic number.

It is not a de Polignac number, because 6221309 - 2²⁰ = 5172733 is a prime.

Together with 6221311, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6221009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3110654 + 3110655.

It is an arithmetic number, because the mean of its divisors is an integer number (3110655).

Almost surely, 2^6221309 is an apocalyptic number.

It is an amenable number.

6221309 is a deficient number, since it is larger than the sum of its proper divisors (1).

6221309 is an equidigital number, since it uses as much as digits as its factorization.

6221309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 6221309 is about 2494.2551994533. The cubic root of 6221309 is about 183.9192797321.

The spelling of 6221309 in words is "six million, two hundred twenty-one thousand, three hundred nine".