15503 has 4 divisors (see below), whose sum is σ = 15960. Its totient is φ = 15048.

The previous prime is 15497. The next prime is 15511. The reversal of 15503 is 30551.

15503 is nontrivially palindromic in base 4.

15503 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 30551 = 137 ⋅223.

It is a cyclic number.

It is not a de Polignac number, because 15503 - 2⁶ = 15439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15583) 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, 173 + ... + 246.

It is an arithmetic number, because the mean of its divisors is an integer number (3990).

2¹⁵⁵⁰³ is an apocalyptic number.

15503 is a deficient number, since it is larger than the sum of its proper divisors (457).

15503 is an equidigital number, since it uses as much as digits as its factorization.

15503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456.

The product of its (nonzero) digits is 75, while the sum is 14.

The square root of 15503 is about 124.5110436869. The cubic root of 15503 is about 24.9347632481.

The spelling of 15503 in words is "fifteen thousand, five hundred three".