15563 has 4 divisors (see below), whose sum is σ = 15840. Its totient is φ = 15288.

The previous prime is 15559. The next prime is 15569. The reversal of 15563 is 36551.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15563 - 2² = 15559 is a prime.

It is a Duffinian number.

15563 is an undulating number in base 14.

It is not an unprimeable number, because it can be changed into a prime (15569) 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, 20 + ... + 177.

It is an arithmetic number, because the mean of its divisors is an integer number (3960).

2¹⁵⁵⁶³ is an apocalyptic number.

15563 is a deficient number, since it is larger than the sum of its proper divisors (277).

15563 is an equidigital number, since it uses as much as digits as its factorization.

15563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 276.

The product of its digits is 450, while the sum is 20.

The square root of 15563 is about 124.7517534947. The cubic root of 15563 is about 24.9668895005.

The spelling of 15563 in words is "fifteen thousand, five hundred sixty-three".