66993671 has 2 divisors, whose sum is σ = 66993672. Its totient is φ = 66993670.

The previous prime is 66993637. The next prime is 66993679. The reversal of 66993671 is 17639966.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66993671 - 2⁶ = 66993607 is a prime.

It is a super-3 number, since 3×66993671³ (a number of 24 digits) contains 333 as substring.

It is a Chen prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66993679) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33496835 + 33496836.

It is an arithmetic number, because the mean of its divisors is an integer number (33496836).

Almost surely, 2^66993671 is an apocalyptic number.

66993671 is a deficient number, since it is larger than the sum of its proper divisors (1).

66993671 is an equidigital number, since it uses as much as digits as its factorization.

66993671 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 367416, while the sum is 47.

The square root of 66993671 is about 8184.9661575354. The cubic root of 66993671 is about 406.1420208170.

The spelling of 66993671 in words is "sixty-six million, nine hundred ninety-three thousand, six hundred seventy-one".