1603 has 4 divisors (see below), whose sum is σ = 1840. Its totient is φ = 1368.

The previous prime is 1601. The next prime is 1607. The reversal of 1603 is 3061.

1603 = 12² + 13² + ... + 18².

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 1603 - 2¹ = 1601 is a prime.

It is a Duffinian number.

It is a plaindrome in base 11.

It is a nialpdrome in base 13 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 1603.

It is not an unprimeable number, because it can be changed into a prime (1601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108 + ... + 121.

It is an arithmetic number, because the mean of its divisors is an integer number (460).

1603 is a deficient number, since it is larger than the sum of its proper divisors (237).

1603 is an equidigital number, since it uses as much as digits as its factorization.

1603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236.

The product of its (nonzero) digits is 18, while the sum is 10.

The square root of 1603 is about 40.0374824383. The cubic root of 1603 is about 11.7033764332.

Adding to 1603 its reverse (3061), we get a palindrome (4664).

The spelling of 1603 in words is "one thousand, six hundred three".