65991966 has 8 divisors (see below), whose sum is σ = 131983944. Its totient is φ = 21997320.

The previous prime is 65991953. The next prime is 65992013. The reversal of 65991966 is 66919956.

It is a sphenic number, since it is the product of 3 distinct primes.

65991966 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5499325 + ... + 5499336.

It is an arithmetic number, because the mean of its divisors is an integer number (16497993).

Almost surely, 2^65991966 is an apocalyptic number.

65991966 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

65991966 is a wasteful number, since it uses less digits than its factorization.

65991966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10998666.

The product of its digits is 787320, while the sum is 51.

The square root of 65991966 is about 8123.5439310685. The cubic root of 65991966 is about 404.1076037593.

The spelling of 65991966 in words is "sixty-five million, nine hundred ninety-one thousand, nine hundred sixty-six".