66985907 has 6 divisors (see below), whose sum is σ = 67490748. Its totient is φ = 66484812.

The previous prime is 66985903. The next prime is 66985909. The reversal of 66985907 is 70958966.

It is not a de Polignac number, because 66985907 - 2² = 66985903 is a prime.

It is a super-2 number, since 2×66985907² = 8974223473225298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66985901) 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 in 5 ways as a sum of consecutive naturals, for example, 17588 + ... + 21054.

It is an arithmetic number, because the mean of its divisors is an integer number (11248458).

Almost surely, 2^66985907 is an apocalyptic number.

66985907 is a deficient number, since it is larger than the sum of its proper divisors (504841).

66985907 is an equidigital number, since it uses as much as digits as its factorization.

66985907 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3745 (or 3606 counting only the distinct ones).

The product of its (nonzero) digits is 816480, while the sum is 50.

The square root of 66985907 is about 8184.4918596086. The cubic root of 66985907 is about 406.1263307355.

The spelling of 66985907 in words is "sixty-six million, nine hundred eighty-five thousand, nine hundred seven".