6631665791 has 2 divisors, whose sum is σ = 6631665792. Its totient is φ = 6631665790.

The previous prime is 6631665787. The next prime is 6631665851. The reversal of 6631665791 is 1975661366.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 6631665791 - 2² = 6631665787 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6631665701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3315832895 + 3315832896.

It is an arithmetic number, because the mean of its divisors is an integer number (3315832896).

Almost surely, 2^6631665791 is an apocalyptic number.

6631665791 is a deficient number, since it is larger than the sum of its proper divisors (1).

6631665791 is an equidigital number, since it uses as much as digits as its factorization.

6631665791 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1224720, while the sum is 50.

The square root of 6631665791 is about 81435.0403143512. The cubic root of 6631665791 is about 1878.7725682519.

The spelling of 6631665791 in words is "six billion, six hundred thirty-one million, six hundred sixty-five thousand, seven hundred ninety-one".