6666801007591 has 2 divisors, whose sum is σ = 6666801007592. Its totient is φ = 6666801007590.

The previous prime is 6666801007553. The next prime is 6666801007609. The reversal of 6666801007591 is 1957001086666.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 6666801007591 - 2⁹ = 6666801007079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6666801007991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3333400503795 + 3333400503796.

It is an arithmetic number, because the mean of its divisors is an integer number (3333400503796).

Almost surely, 2^{6666801007591} is an apocalyptic number.

6666801007591 is a deficient number, since it is larger than the sum of its proper divisors (1).

6666801007591 is an equidigital number, since it uses as much as digits as its factorization.

6666801007591 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3265920, while the sum is 55.

The spelling of 6666801007591 in words is "six trillion, six hundred sixty-six billion, eight hundred one million, seven thousand, five hundred ninety-one".