665540636 has 12 divisors (see below), whose sum is σ = 1165646328. Its totient is φ = 332498832.

The previous prime is 665540609. The next prime is 665540669. The reversal of 665540636 is 636045566.

It is a happy number.

665540636 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 665540593 and 665540602.

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, 62306 + ... + 72201.

It is an arithmetic number, because the mean of its divisors is an integer number (97137194).

Almost surely, 2^665540636 is an apocalyptic number.

It is an amenable number.

665540636 is a deficient number, since it is larger than the sum of its proper divisors (500105692).

665540636 is a wasteful number, since it uses less digits than its factorization.

665540636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135748 (or 135746 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 41.

The square root of 665540636 is about 25798.0742692163. The cubic root of 665540636 is about 873.0883483666.

The spelling of 665540636 in words is "six hundred sixty-five million, five hundred forty thousand, six hundred thirty-six".