665915959 has 8 divisors (see below), whose sum is σ = 705498768. Its totient is φ = 626378880.

The previous prime is 665915953. The next prime is 665915969. The reversal of 665915959 is 959519566.

It is a happy number.

665915959 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665915959 - 2²¹ = 663818807 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665915953) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21249 + ... + 42229.

It is an arithmetic number, because the mean of its divisors is an integer number (88187346).

Almost surely, 2^665915959 is an apocalyptic number.

665915959 is a deficient number, since it is larger than the sum of its proper divisors (39582809).

665915959 is a wasteful number, since it uses less digits than its factorization.

665915959 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22865.

The product of its digits is 3280500, while the sum is 55.

The square root of 665915959 is about 25805.3474884567. The cubic root of 665915959 is about 873.2524398039.

The spelling of 665915959 in words is "six hundred sixty-five million, nine hundred fifteen thousand, nine hundred fifty-nine".