15623 has 4 divisors (see below), whose sum is σ = 16560. Its totient is φ = 14688.

The previous prime is 15619. The next prime is 15629. The reversal of 15623 is 32651.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32651 = 103 ⋅317.

It is not a de Polignac number, because 15623 - 2² = 15619 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 919 = 15623 / (1 + 5 + 6 + 2 + 3).

It is a Duffinian number.

It is a plaindrome in base 9 and base 14.

It is a nialpdrome in base 5.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15629) 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, 443 + ... + 476.

It is an arithmetic number, because the mean of its divisors is an integer number (4140).

15623 is a Friedman number, since it can be written as 5^6-3+2-1, using all its digits and the basic arithmetic operations.

2¹⁵⁶²³ is an apocalyptic number.

15623 is a deficient number, since it is larger than the sum of its proper divisors (937).

15623 is an equidigital number, since it uses as much as digits as its factorization.

15623 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936.

The product of its digits is 180, while the sum is 17.

The square root of 15623 is about 124.9919997440. The cubic root of 15623 is about 24.9989332878.

15623 divided by its sum of digits (17) gives a palindrome (919).

The spelling of 15623 in words is "fifteen thousand, six hundred twenty-three".