20903 has 2 divisors, whose sum is σ = 20904. Its totient is φ = 20902.

The previous prime is 20899. The next prime is 20921. The reversal of 20903 is 30902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20903 - 2² = 20899 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20963) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10451 + 10452.

It is an arithmetic number, because the mean of its divisors is an integer number (10452).

2²⁰⁹⁰³ is an apocalyptic number.

20903 is a deficient number, since it is larger than the sum of its proper divisors (1).

20903 is an equidigital number, since it uses as much as digits as its factorization.

20903 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 14.

The square root of 20903 is about 144.5786982927. The cubic root of 20903 is about 27.5466975180.

Subtracting 20903 from its reverse (30902), we obtain a palindrome (9999).

The spelling of 20903 in words is "twenty thousand, nine hundred three".