6211866809 has 2 divisors, whose sum is σ = 6211866810. Its totient is φ = 6211866808.

The previous prime is 6211866781. The next prime is 6211866811. The reversal of 6211866809 is 9086681126.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3803805625 + 2408061184 = 61675^2 + 49072^2 .

It is a cyclic number.

It is not a de Polignac number, because 6211866809 - 2¹⁶ = 6211801273 is a prime.

Together with 6211866811, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (6211866839) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3105933404 + 3105933405.

It is an arithmetic number, because the mean of its divisors is an integer number (3105933405).

Almost surely, 2^6211866809 is an apocalyptic number.

It is an amenable number.

6211866809 is a deficient number, since it is larger than the sum of its proper divisors (1).

6211866809 is an equidigital number, since it uses as much as digits as its factorization.

6211866809 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 248832, while the sum is 47.

The square root of 6211866809 is about 78815.3970300220. The cubic root of 6211866809 is about 1838.2618676904.

The spelling of 6211866809 in words is "six billion, two hundred eleven million, eight hundred sixty-six thousand, eight hundred nine".