66667945543 has 2 divisors, whose sum is σ = 66667945544. Its totient is φ = 66667945542.

The previous prime is 66667945537. The next prime is 66667945607. The reversal of 66667945543 is 34554976666.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 66667945543 - 2⁵ = 66667945511 is a prime.

It is a super-2 number, since 2×66667945543² (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 (66667915543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33333972771 + 33333972772.

It is an arithmetic number, because the mean of its divisors is an integer number (33333972772).

Almost surely, 2^66667945543 is an apocalyptic number.

66667945543 is a deficient number, since it is larger than the sum of its proper divisors (1).

66667945543 is an equidigital number, since it uses as much as digits as its factorization.

66667945543 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 97977600, while the sum is 61.

The spelling of 66667945543 in words is "sixty-six billion, six hundred sixty-seven million, nine hundred forty-five thousand, five hundred forty-three".