665982765 has 72 divisors (see below), whose sum is σ = 1386298368. Its totient is φ = 294598080.

The previous prime is 665982763. The next prime is 665982773. The reversal of 665982765 is 567289566.

It is a happy number.

It is not a de Polignac number, because 665982765 - 2¹ = 665982763 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665982761) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 63484 + ... + 73226.

It is an arithmetic number, because the mean of its divisors is an integer number (19254144).

Almost surely, 2^665982765 is an apocalyptic number.

It is an amenable number.

665982765 is an abundant number, since it is smaller than the sum of its proper divisors (720315603).

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

665982765 is a wasteful number, since it uses less digits than its factorization.

665982765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9799 (or 9789 counting only the distinct ones).

The product of its digits is 5443200, while the sum is 54.

The square root of 665982765 is about 25806.6418776252. The cubic root of 665982765 is about 873.2816409621.

The spelling of 665982765 in words is "six hundred sixty-five million, nine hundred eighty-two thousand, seven hundred sixty-five".