20387 has 8 divisors (see below), whose sum is σ = 22800. Its totient is φ = 18144.

The previous prime is 20369. The next prime is 20389. The reversal of 20387 is 78302.

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

It is a cyclic number.

It is not a de Polignac number, because 20387 - 2⁶ = 20323 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 533 + ... + 569.

It is an arithmetic number, because the mean of its divisors is an integer number (2850).

2²⁰³⁸⁷ is an apocalyptic number.

20387 is a deficient number, since it is larger than the sum of its proper divisors (2413).

20387 is a wasteful number, since it uses less digits than its factorization.

20387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 85.

The product of its (nonzero) digits is 336, while the sum is 20.

The square root of 20387 is about 142.7830522156. The cubic root of 20387 is about 27.3181388218.

Adding to 20387 its reverse (78302), we get a palindrome (98689).

The spelling of 20387 in words is "twenty thousand, three hundred eighty-seven".