8217659491 has 2 divisors, whose sum is σ = 8217659492. Its totient is φ = 8217659490.

The previous prime is 8217659441. The next prime is 8217659531. The reversal of 8217659491 is 1949567128.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 8217659491 - 2⁷ = 8217659363 is a prime.

It is not a weakly prime, because it can be changed into another prime (8217659431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4108829745 + 4108829746.

It is an arithmetic number, because the mean of its divisors is an integer number (4108829746).

Almost surely, 2^8217659491 is an apocalyptic number.

8217659491 is a deficient number, since it is larger than the sum of its proper divisors (1).

8217659491 is an equidigital number, since it uses as much as digits as its factorization.

8217659491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 52.

The square root of 8217659491 is about 90651.3071665268. The cubic root of 8217659491 is about 2017.9762343386.

The spelling of 8217659491 in words is "eight billion, two hundred seventeen million, six hundred fifty-nine thousand, four hundred ninety-one".