6211866805 has 4 divisors (see below), whose sum is σ = 7454240172. Its totient is φ = 4969493440.

The previous prime is 6211866781. The next prime is 6211866809. The reversal of 6211866805 is 5086681126.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1437471396 + 4774395409 = 37914^2 + 69097^2 .

It is not a de Polignac number, because 6211866805 - 2⁹ = 6211866293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6211866809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 621186676 + ... + 621186685.

It is an arithmetic number, because the mean of its divisors is an integer number (1863560043).

Almost surely, 2^6211866805 is an apocalyptic number.

It is an amenable number.

6211866805 is a deficient number, since it is larger than the sum of its proper divisors (1242373367).

6211866805 is a wasteful number, since it uses less digits than its factorization.

6211866805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1242373366.

The product of its (nonzero) digits is 138240, while the sum is 43.

The square root of 6211866805 is about 78815.3970046462. The cubic root of 6211866805 is about 1838.2618672958.

The spelling of 6211866805 in words is "six billion, two hundred eleven million, eight hundred sixty-six thousand, eight hundred five".