20159 has 4 divisors (see below), whose sum is σ = 21240. Its totient is φ = 19080.

The previous prime is 20149. The next prime is 20161. The reversal of 20159 is 95102.

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 20159 - 2⁴ = 20143 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 (20129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 512 + ... + 549.

It is an arithmetic number, because the mean of its divisors is an integer number (5310).

2²⁰¹⁵⁹ is an apocalyptic number.

20159 is a deficient number, since it is larger than the sum of its proper divisors (1081).

20159 is a wasteful number, since it uses less digits than its factorization.

20159 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080.

The product of its (nonzero) digits is 90, while the sum is 17.

The square root of 20159 is about 141.9823932747. The cubic root of 20159 is about 27.2159184503.

The spelling of 20159 in words is "twenty thousand, one hundred fifty-nine".