1003 has 4 divisors (see below), whose sum is σ = 1080. Its totient is φ = 928.

The previous prime is 997. The next prime is 1009. The reversal of 1003 is 3001.

It is a happy number.

1003 is nontrivially palindromic in base 3.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is an interprime number because it is at equal distance from previous prime (997) and next prime (1009).

It is a cyclic number.

It is not a de Polignac number, because 1003 - 2⁵ = 971 is a prime.

It is a Duffinian number.

1003 is a modest number, since divided by 3 gives 1 as remainder.

It is a plaindrome in base 9 and base 15.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 983 and 1001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1009) 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, 13 + ... + 46.

It is an arithmetic number, because the mean of its divisors is an integer number (270).

1003 is a deficient number, since it is larger than the sum of its proper divisors (77).

1003 is an equidigital number, since it uses as much as digits as its factorization.

1003 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76.

The product of its (nonzero) digits is 3, while the sum is 4.

The square root of 1003 is about 31.6701752442. The cubic root of 1003 is about 10.0099900166.

Adding to 1003 its reverse (3001), we get a palindrome (4004).

It can be divided in two parts, 100 and 3, that multiplied together give a triangular number (300 = T₂₄).

The spelling of 1003 in words is "one thousand, three", and thus it is an iban number.