665640733136 has 20 divisors (see below), whose sum is σ = 1290703327200. Its totient is φ = 332556003552.

The previous prime is 665640733073. The next prime is 665640733151. The reversal of 665640733136 is 631337046566.

It is a happy number.

It is a Smith number, since the sum of its digits (50) coincides with the sum of the digits of its prime factors.

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, 16501916 + ... + 16542203.

It is an arithmetic number, because the mean of its divisors is an integer number (64535166360).

Almost surely, 2^665640733136 is an apocalyptic number.

It is an amenable number.

665640733136 is a deficient number, since it is larger than the sum of its proper divisors (625062594064).

665640733136 is a wasteful number, since it uses less digits than its factorization.

665640733136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33045386 (or 33045380 counting only the distinct ones).

The product of its (nonzero) digits is 4898880, while the sum is 50.

The spelling of 665640733136 in words is "six hundred sixty-five billion, six hundred forty million, seven hundred thirty-three thousand, one hundred thirty-six".