665603 has 2 divisors, whose sum is σ = 665604. Its totient is φ = 665602.

The previous prime is 665591. The next prime is 665617. The reversal of 665603 is 306566.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 665603 - 2¹⁰ = 664579 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (665633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 332801 + 332802.

It is an arithmetic number, because the mean of its divisors is an integer number (332802).

2⁶⁶⁵⁶⁰³ is an apocalyptic number.

665603 is a deficient number, since it is larger than the sum of its proper divisors (1).

665603 is an equidigital number, since it uses as much as digits as its factorization.

665603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3240, while the sum is 26.

The square root of 665603 is about 815.8449607615. The cubic root of 665603 is about 87.3115618217.

The spelling of 665603 in words is "six hundred sixty-five thousand, six hundred three".