6503 has 4 divisors (see below), whose sum is σ = 7440. Its totient is φ = 5568.

The previous prime is 6491. The next prime is 6521. The reversal of 6503 is 3056.

It is a happy number.

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 6503 - 2⁸ = 6247 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6553) 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, 458 + ... + 471.

It is an arithmetic number, because the mean of its divisors is an integer number (1860).

2⁶⁵⁰³ is an apocalyptic number.

6503 is a deficient number, since it is larger than the sum of its proper divisors (937).

6503 is an equidigital number, since it uses as much as digits as its factorization.

6503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936.

The product of its (nonzero) digits is 90, while the sum is 14.

The square root of 6503 is about 80.6411805469. The cubic root of 6503 is about 18.6654265049.

Adding to 6503 its reverse (3056), we get a palindrome (9559).

The spelling of 6503 in words is "six thousand, five hundred three".