66917687 has 2 divisors, whose sum is σ = 66917688. Its totient is φ = 66917686.

The previous prime is 66917663. The next prime is 66917689. The reversal of 66917687 is 78671966.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66917687 - 2¹² = 66913591 is a prime.

Together with 66917689, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66917689) 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, 33458843 + 33458844.

It is an arithmetic number, because the mean of its divisors is an integer number (33458844).

Almost surely, 2^66917687 is an apocalyptic number.

66917687 is a deficient number, since it is larger than the sum of its proper divisors (1).

66917687 is an equidigital number, since it uses as much as digits as its factorization.

66917687 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 762048, while the sum is 50.

The square root of 66917687 is about 8180.3231598758. The cubic root of 66917687 is about 405.9884144170.

The spelling of 66917687 in words is "sixty-six million, nine hundred seventeen thousand, six hundred eighty-seven".