503 has 2 divisors, whose sum is σ = 504. Its totient is φ = 502.

The previous prime is 499. The next prime is 509. The reversal of 503 is 305.

503 is nontrivially palindromic in base 8.

503 is an esthetic number in base 8, because in such base its adjacent digits differ by 1.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 503 - 2² = 499 is a prime.

It is a Chen prime.

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

503 is an undulating number in base 8.

It is a plaindrome in base 12, base 14 and base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 251 + 252.

It is an arithmetic number, because the mean of its divisors is an integer number (252).

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

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

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

The product of its (nonzero) digits is 15, while the sum is 8.

The square root of 503 is about 22.4276614920. The cubic root of 503 is about 7.9528476277.

Adding to 503 its reverse (305), we get a palindrome (808).

The spelling of 503 in words is "five hundred three", and thus it is an aban number and an oban number.