665940517 has 8 divisors (see below), whose sum is σ = 730247040. Its totient is φ = 602261760.

The previous prime is 665940503. The next prime is 665940547. The reversal of 665940517 is 715049566.

665940517 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 a de Polignac number, because none of the positive numbers 2^k-665940517 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 (665940547) 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, 154717 + ... + 158962.

It is an arithmetic number, because the mean of its divisors is an integer number (91280880).

Almost surely, 2^665940517 is an apocalyptic number.

It is an amenable number.

665940517 is a deficient number, since it is larger than the sum of its proper divisors (64306523).

665940517 is a wasteful number, since it uses less digits than its factorization.

665940517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313883.

The product of its (nonzero) digits is 226800, while the sum is 43.

The square root of 665940517 is about 25805.8233156782. The cubic root of 665940517 is about 873.2631744266.

The spelling of 665940517 in words is "six hundred sixty-five million, nine hundred forty thousand, five hundred seventeen".