665716501 has 4 divisors (see below), whose sum is σ = 672179872. Its totient is φ = 659253132.

The previous prime is 665716487. The next prime is 665716559. The reversal of 665716501 is 105617566.

665716501 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 665716501 - 2⁹ = 665715989 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 (665716591) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3231531 + ... + 3231736.

It is an arithmetic number, because the mean of its divisors is an integer number (168044968).

Almost surely, 2^665716501 is an apocalyptic number.

It is an amenable number.

665716501 is a deficient number, since it is larger than the sum of its proper divisors (6463371).

665716501 is a wasteful number, since it uses less digits than its factorization.

665716501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6463370.

The product of its (nonzero) digits is 37800, while the sum is 37.

The square root of 665716501 is about 25801.4825349242. The cubic root of 665716501 is about 873.1652443274.

The spelling of 665716501 in words is "six hundred sixty-five million, seven hundred sixteen thousand, five hundred one".