665903 has 8 divisors (see below), whose sum is σ = 766080. Its totient is φ = 567000.

The previous prime is 665897. The next prime is 665921. The reversal of 665903 is 309566.

665903 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 not a de Polignac number, because 665903 - 2¹⁰ = 664879 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665923) 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, 1568 + ... + 1946.

It is an arithmetic number, because the mean of its divisors is an integer number (95760).

2⁶⁶⁵⁹⁰³ is an apocalyptic number.

665903 is a deficient number, since it is larger than the sum of its proper divisors (100177).

665903 is a wasteful number, since it uses less digits than its factorization.

665903 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637.

The product of its (nonzero) digits is 4860, while the sum is 29.

The square root of 665903 is about 816.0287985114. The cubic root of 665903 is about 87.3246775149.

The spelling of 665903 in words is "six hundred sixty-five thousand, nine hundred three".