6645789791 has 2 divisors, whose sum is σ = 6645789792. Its totient is φ = 6645789790.

The previous prime is 6645789781. The next prime is 6645789797. The reversal of 6645789791 is 1979875466.

6645789791 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6645789791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6645789797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3322894895 + 3322894896.

It is an arithmetic number, because the mean of its divisors is an integer number (3322894896).

Almost surely, 2^6645789791 is an apocalyptic number.

6645789791 is a deficient number, since it is larger than the sum of its proper divisors (1).

6645789791 is an equidigital number, since it uses as much as digits as its factorization.

6645789791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 22861440, while the sum is 62.

The square root of 6645789791 is about 81521.7136166801. The cubic root of 6645789791 is about 1880.1054142453.

The spelling of 6645789791 in words is "six billion, six hundred forty-five million, seven hundred eighty-nine thousand, seven hundred ninety-one".