665382785641 has 4 divisors (see below), whose sum is σ = 760437469312. Its totient is φ = 570328101972.

The previous prime is 665382785629. The next prime is 665382785663. The reversal of 665382785641 is 146587283566.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 665382785641 - 2¹⁹ = 665382261353 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665382785641.

It is not an unprimeable number, because it can be changed into a prime (665382785741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47527341825 + ... + 47527341838.

It is an arithmetic number, because the mean of its divisors is an integer number (190109367328).

Almost surely, 2^665382785641 is an apocalyptic number.

It is an amenable number.

665382785641 is a deficient number, since it is larger than the sum of its proper divisors (95054683671).

665382785641 is an equidigital number, since it uses as much as digits as its factorization.

665382785641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95054683670.

The product of its digits is 58060800, while the sum is 61.

The spelling of 665382785641 in words is "six hundred sixty-five billion, three hundred eighty-two million, seven hundred eighty-five thousand, six hundred forty-one".