31903 has 4 divisors (see below), whose sum is σ = 32488. Its totient is φ = 31320.

The previous prime is 31891. The next prime is 31907. The reversal of 31903 is 30913.

It is a happy number.

31903 is nontrivially palindromic in base 2.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30913 = 19 ⋅1627.

It is a cyclic number.

It is not a de Polignac number, because 31903 - 2⁹ = 31391 is a prime.

It is an Ulam number.

It is a Duffinian number.

31903 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31907) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201 + ... + 322.

It is an arithmetic number, because the mean of its divisors is an integer number (8122).

2³¹⁹⁰³ is an apocalyptic number.

31903 is a deficient number, since it is larger than the sum of its proper divisors (585).

31903 is an equidigital number, since it uses as much as digits as its factorization.

31903 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 584.

The product of its (nonzero) digits is 81, while the sum is 16.

The square root of 31903 is about 178.6141091851. The cubic root of 31903 is about 31.7159098422.

Subtracting from 31903 its reverse (30913), we obtain a triangular number (990 = T₄₄).

The spelling of 31903 in words is "thirty-one thousand, nine hundred three".