65691666 has 24 divisors (see below), whose sum is σ = 146924544. Its totient is φ = 21190680.

The previous prime is 65691631. The next prime is 65691667. The reversal of 65691666 is 66619656.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (65691667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 58306 + ... + 59421.

It is an arithmetic number, because the mean of its divisors is an integer number (6121856).

Almost surely, 2^65691666 is an apocalyptic number.

65691666 is an abundant number, since it is smaller than the sum of its proper divisors (81232878).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65691666 is a wasteful number, since it uses less digits than its factorization.

65691666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117766 (or 117763 counting only the distinct ones).

The product of its digits is 349920, while the sum is 45.

The square root of 65691666 is about 8105.0395433952. The cubic root of 65691666 is about 403.4937004678.

The spelling of 65691666 in words is "sixty-five million, six hundred ninety-one thousand, six hundred sixty-six".