663503 has 4 divisors (see below), whose sum is σ = 679728. Its totient is φ = 647280.

The previous prime is 663463. The next prime is 663517. The reversal of 663503 is 305366.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 663503 - 2¹⁶ = 597967 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 (663563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8051 + ... + 8132.

It is an arithmetic number, because the mean of its divisors is an integer number (169932).

2⁶⁶³⁵⁰³ is an apocalyptic number.

663503 is a deficient number, since it is larger than the sum of its proper divisors (16225).

663503 is a wasteful number, since it uses less digits than its factorization.

663503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16224.

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 663503 is about 814.5569347811. The cubic root of 663503 is about 87.2196414387.

Adding to 663503 its reverse (305366), we get a palindrome (968869).

The spelling of 663503 in words is "six hundred sixty-three thousand, five hundred three".