8149191691 has 2 divisors, whose sum is σ = 8149191692. Its totient is φ = 8149191690.

The previous prime is 8149191667. The next prime is 8149191703. The reversal of 8149191691 is 1961919418.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8149191691 - 2¹⁹ = 8148667403 is a prime.

It is not a weakly prime, because it can be changed into another prime (8149191641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4074595845 + 4074595846.

It is an arithmetic number, because the mean of its divisors is an integer number (4074595846).

Almost surely, 2^8149191691 is an apocalyptic number.

8149191691 is a deficient number, since it is larger than the sum of its proper divisors (1).

8149191691 is an equidigital number, since it uses as much as digits as its factorization.

8149191691 is an evil number, because the sum of its binary digits is even.

The product of its digits is 139968, while the sum is 49.

The square root of 8149191691 is about 90272.8735058323. The cubic root of 8149191691 is about 2012.3561465325.

The spelling of 8149191691 in words is "eight billion, one hundred forty-nine million, one hundred ninety-one thousand, six hundred ninety-one".