6656663591 has 2 divisors, whose sum is σ = 6656663592. Its totient is φ = 6656663590.

The previous prime is 6656663561. The next prime is 6656663617. The reversal of 6656663591 is 1953666566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6656663591 - 2¹⁸ = 6656401447 is a prime.

It is a super-2 number, since 2×6656663591² = 88622340327490030562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6656663561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3328331795 + 3328331796.

It is an arithmetic number, because the mean of its divisors is an integer number (3328331796).

Almost surely, 2^6656663591 is an apocalyptic number.

6656663591 is a deficient number, since it is larger than the sum of its proper divisors (1).

6656663591 is an equidigital number, since it uses as much as digits as its factorization.

6656663591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5248800, while the sum is 53.

The square root of 6656663591 is about 81588.3790193187. The cubic root of 6656663591 is about 1881.1302611015.

The spelling of 6656663591 in words is "six billion, six hundred fifty-six million, six hundred sixty-three thousand, five hundred ninety-one".