1903 has 4 divisors (see below), whose sum is σ = 2088. Its totient is φ = 1720.

The previous prime is 1901. The next prime is 1907. The reversal of 1903 is 3091.

It is a happy number.

1903 is nontrivially palindromic in base 5.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3091 = 11 ⋅281.

It is a cyclic number.

It is not a de Polignac number, because 1903 - 2¹ = 1901 is a prime.

It is a Smith number, since the sum of its digits (13) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a plaindrome in base 8, base 12 and base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1901) 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, 76 + ... + 97.

It is an arithmetic number, because the mean of its divisors is an integer number (522).

2¹⁹⁰³ is an apocalyptic number.

1903 is a deficient number, since it is larger than the sum of its proper divisors (185).

1903 is a wasteful number, since it uses less digits than its factorization.

1903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 184.

The product of its (nonzero) digits is 27, while the sum is 13.

The square root of 1903 is about 43.6233882224. The cubic root of 1903 is about 12.3921386175.

Adding to 1903 its reverse (3091), we get a palindrome (4994).

The spelling of 1903 in words is "one thousand, nine hundred three".