66998063791 has 2 divisors, whose sum is σ = 66998063792. Its totient is φ = 66998063790.

The previous prime is 66998063779. The next prime is 66998063813. The reversal of 66998063791 is 19736089966.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66998063791 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66998063591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33499031895 + 33499031896.

It is an arithmetic number, because the mean of its divisors is an integer number (33499031896).

Almost surely, 2^66998063791 is an apocalyptic number.

66998063791 is a deficient number, since it is larger than the sum of its proper divisors (1).

66998063791 is an equidigital number, since it uses as much as digits as its factorization.

66998063791 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26453952, while the sum is 64.

The spelling of 66998063791 in words is "sixty-six billion, nine hundred ninety-eight million, sixty-three thousand, seven hundred ninety-one".