20006 has 8 divisors (see below), whose sum is σ = 34320. Its totient is φ = 8568.

The previous prime is 19997. The next prime is 20011. The reversal of 20006 is 60002.

It is a sphenic number, since it is the product of 3 distinct primes.

20006 is a modest number, since divided by 6 gives 2 as remainder.

It is a Curzon number.

It is a nialpdrome in base 14.

It is a junction number, because it is equal to n+sod(n) for n = 19975 and 20002.

It is a congruent number.

It is an unprimeable number.

20006 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 in 3 ways as a sum of consecutive naturals, for example, 701 + ... + 728.

It is an arithmetic number, because the mean of its divisors is an integer number (4290).

2²⁰⁰⁰⁶ is an apocalyptic number.

20006 is a deficient number, since it is larger than the sum of its proper divisors (14314).

20006 is a wasteful number, since it uses less digits than its factorization.

20006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1438.

The product of its (nonzero) digits is 12, while the sum is 8.

The square root of 20006 is about 141.4425678500. The cubic root of 20006 is about 27.1468903122.

Adding to 20006 its reverse (60002), we get a palindrome (80008).

The spelling of 20006 in words is "twenty thousand, six".