66546546640109 has 2 divisors, whose sum is σ = 66546546640110. Its totient is φ = 66546546640108.

The previous prime is 66546546640043. The next prime is 66546546640151. The reversal of 66546546640109 is 90104664564566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 66464022587209 + 82524052900 = 8152547^2 + 287270^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66546546640109 is a prime.

It is a super-4 number, since 4×66546546640109⁴ (a number of 56 digits) contains 4444 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66546546640169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33273273320054 + 33273273320055.

It is an arithmetic number, because the mean of its divisors is an integer number (33273273320055).

Almost surely, 2^{66546546640109} is an apocalyptic number.

It is an amenable number.

66546546640109 is a deficient number, since it is larger than the sum of its proper divisors (1).

66546546640109 is an equidigital number, since it uses as much as digits as its factorization.

66546546640109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 111974400, while the sum is 62.

The spelling of 66546546640109 in words is "sixty-six trillion, five hundred forty-six billion, five hundred forty-six million, six hundred forty thousand, one hundred nine".