8191191947 has 2 divisors, whose sum is σ = 8191191948. Its totient is φ = 8191191946.

The previous prime is 8191191941. The next prime is 8191191977. The reversal of 8191191947 is 7491911918.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8191191947 - 2²⁶ = 8124083083 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8191191895 and 8191191904.

It is not a weakly prime, because it can be changed into another prime (8191191941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4095595973 + 4095595974.

It is an arithmetic number, because the mean of its divisors is an integer number (4095595974).

Almost surely, 2^8191191947 is an apocalyptic number.

8191191947 is a deficient number, since it is larger than the sum of its proper divisors (1).

8191191947 is an equidigital number, since it uses as much as digits as its factorization.

8191191947 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 163296, while the sum is 50.

The square root of 8191191947 is about 90505.2039774509. The cubic root of 8191191947 is about 2015.8073962081.

The spelling of 8191191947 in words is "eight billion, one hundred ninety-one million, one hundred ninety-one thousand, nine hundred forty-seven".