15689 has 4 divisors (see below), whose sum is σ = 16260. Its totient is φ = 15120.

The previous prime is 15683. The next prime is 15727. The reversal of 15689 is 98651.

15689 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.

It can be written as a sum of positive squares in 2 ways, for example, as 7225 + 8464 = 85^2 + 92^2 .

It is a sliding number, since 15689 = 64 + 15625 and 1/64 + 1/15625 = 0.015689.

It is a cyclic number.

It is not a de Polignac number, because 15689 - 2^{12} = 11593 is a prime.

It is a super-2 number, since 2×15689^{2} = 492289442, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29), and also a Moran number because the ratio is a prime number: 541 = 15689 / (1 + 5 + 6 + 8 + 9).

It is a Duffinian number.

It is a Curzon number.

It is a plaindrome in base 10 and base 15.

It is not an unprimeable number, because it can be changed into a prime (15683) 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, 242 + ... + 299.

It is an arithmetic number, because the mean of its divisors is an integer number (4065).

15689 is a Friedman number, since it can be written as 5^6+8*(9-1), using all its digits and the basic arithmetic operations.

2^{15689} is an apocalyptic number.

It is an amenable number.

15689 is a deficient number, since it is larger than the sum of its proper divisors (571).

15689 is an equidigital number, since it uses as much as digits as its factorization.

15689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570.

The product of its digits is 2160, while the sum is 29.

The square root of 15689 is about 125.2557383915. The cubic root of 15689 is about 25.0340868357.

The spelling of 15689 in words is "fifteen thousand, six hundred eighty-nine".

• e-mail: info -at- numbersaplenty.com • Privacy notice • done in 0.059 sec. • engine limits •