8278205891 has 2 divisors, whose sum is σ = 8278205892. Its totient is φ = 8278205890.

The previous prime is 8278205863. The next prime is 8278205899. The reversal of 8278205891 is 1985028728.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8278205891 - 2²² = 8274011587 is a prime.

It is not a weakly prime, because it can be changed into another prime (8278205899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4139102945 + 4139102946.

It is an arithmetic number, because the mean of its divisors is an integer number (4139102946).

Almost surely, 2^8278205891 is an apocalyptic number.

8278205891 is a deficient number, since it is larger than the sum of its proper divisors (1).

8278205891 is an equidigital number, since it uses as much as digits as its factorization.

8278205891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 645120, while the sum is 50.

The square root of 8278205891 is about 90984.6464575205. The cubic root of 8278205891 is about 2022.9201541238.

The spelling of 8278205891 in words is "eight billion, two hundred seventy-eight million, two hundred five thousand, eight hundred ninety-one".