18503 has 2 divisors, whose sum is σ = 18504. Its totient is φ = 18502.

The previous prime is 18493. The next prime is 18517. The reversal of 18503 is 30581.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 18503 - 2⁶ = 18439 is a prime.

It is a super-2 number, since 2×18503² = 684722018, which contains 22 as substring.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (18523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9251 + 9252.

It is an arithmetic number, because the mean of its divisors is an integer number (9252).

2¹⁸⁵⁰³ is an apocalyptic number.

18503 is a deficient number, since it is larger than the sum of its proper divisors (1).

18503 is an equidigital number, since it uses as much as digits as its factorization.

18503 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 18503 is about 136.0257328596. The cubic root of 18503 is about 26.4492919004.

The spelling of 18503 in words is "eighteen thousand, five hundred three".