66555166669 has 2 divisors, whose sum is σ = 66555166670. Its totient is φ = 66555166668.

The previous prime is 66555166661. The next prime is 66555166673. The reversal of 66555166669 is 96666155566.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65928265225 + 626901444 = 256765^2 + 25038^2 .

It is a cyclic number.

It is not a de Polignac number, because 66555166669 - 2³ = 66555166661 is a prime.

It is a super-2 number, since 2×66555166669² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66555166661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33277583334 + 33277583335.

It is an arithmetic number, because the mean of its divisors is an integer number (33277583335).

Almost surely, 2^66555166669 is an apocalyptic number.

It is an amenable number.

66555166669 is a deficient number, since it is larger than the sum of its proper divisors (1).

66555166669 is an equidigital number, since it uses as much as digits as its factorization.

66555166669 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 52488000, while the sum is 61.

The spelling of 66555166669 in words is "sixty-six billion, five hundred fifty-five million, one hundred sixty-six thousand, six hundred sixty-nine".