15506 has 4 divisors (see below), whose sum is σ = 23262. Its totient is φ = 7752.

The previous prime is 15497. The next prime is 15511. The reversal of 15506 is 60551.

15506 is digitally balanced in base 2, 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: 60551 = 151 ⋅401.

It can be written as a sum of positive squares in only one way, i.e., 8281 + 7225 = 91^2 + 85^2 .

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3875 + ... + 3878.

2¹⁵⁵⁰⁶ is an apocalyptic number.

15506 is a deficient number, since it is larger than the sum of its proper divisors (7756).

15506 is an equidigital number, since it uses as much as digits as its factorization.

15506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7755.

The product of its (nonzero) digits is 150, while the sum is 17.

The square root of 15506 is about 124.5230902283. The cubic root of 15506 is about 24.9363715274.

The spelling of 15506 in words is "fifteen thousand, five hundred six".