66667100799991 has 2 divisors, whose sum is σ = 66667100799992. Its totient is φ = 66667100799990.

The previous prime is 66667100799973. The next prime is 66667100799997. The reversal of 66667100799991 is 19999700176666.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66667100799991 - 2⁹ = 66667100799479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66667100799997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333550399995 + 33333550399996.

It is an arithmetic number, because the mean of its divisors is an integer number (33333550399996).

Almost surely, 2^{66667100799991} is an apocalyptic number.

66667100799991 is a deficient number, since it is larger than the sum of its proper divisors (1).

66667100799991 is an equidigital number, since it uses as much as digits as its factorization.

66667100799991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 416649744, while the sum is 76.

The spelling of 66667100799991 in words is "sixty-six trillion, six hundred sixty-seven billion, one hundred million, seven hundred ninety-nine thousand, nine hundred ninety-one".