8191863487 has 2 divisors, whose sum is σ = 8191863488. Its totient is φ = 8191863486.

The previous prime is 8191863469. The next prime is 8191863523. The reversal of 8191863487 is 7843681918.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 8191863487 - 2¹⁹ = 8191339199 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8191864487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4095931743 + 4095931744.

It is an arithmetic number, because the mean of its divisors is an integer number (4095931744).

Almost surely, 2^8191863487 is an apocalyptic number.

8191863487 is a deficient number, since it is larger than the sum of its proper divisors (1).

8191863487 is an equidigital number, since it uses as much as digits as its factorization.

8191863487 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 55.

The square root of 8191863487 is about 90508.9138538299. The cubic root of 8191863487 is about 2015.8624821392.

The spelling of 8191863487 in words is "eight billion, one hundred ninety-one million, eight hundred sixty-three thousand, four hundred eighty-seven".