665505843 has 16 divisors (see below), whose sum is σ = 892442880. Its totient is φ = 441127904.

The previous prime is 665505823. The next prime is 665505857. The reversal of 665505843 is 348505566.

It is a happy number.

665505843 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is not a de Polignac number, because 665505843 - 2⁸ = 665505587 is a prime.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 665505795 and 665505804.

It is not an unprimeable number, because it can be changed into a prime (665505803) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 652588 + ... + 653606.

It is an arithmetic number, because the mean of its divisors is an integer number (55777680).

Almost surely, 2^665505843 is an apocalyptic number.

665505843 is a deficient number, since it is larger than the sum of its proper divisors (226937037).

665505843 is a wasteful number, since it uses less digits than its factorization.

665505843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2058.

The product of its (nonzero) digits is 432000, while the sum is 42.

The square root of 665505843 is about 25797.3999271244. The cubic root of 665505843 is about 873.0731337222.

The spelling of 665505843 in words is "six hundred sixty-five million, five hundred five thousand, eight hundred forty-three".