19887 has 8 divisors (see below), whose sum is σ = 30336. Its totient is φ = 11352.

The previous prime is 19867. The next prime is 19889. The reversal of 19887 is 78891.

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

It is not a de Polignac number, because 19887 - 2⁷ = 19759 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 19887.

It is not an unprimeable number, because it can be changed into a prime (19889) 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, 453 + ... + 494.

It is an arithmetic number, because the mean of its divisors is an integer number (3792).

2¹⁹⁸⁸⁷ is an apocalyptic number.

19887 is a deficient number, since it is larger than the sum of its proper divisors (10449).

19887 is an equidigital number, since it uses as much as digits as its factorization.

19887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957.

The product of its digits is 4032, while the sum is 33.

The square root of 19887 is about 141.0212749907. The cubic root of 19887 is about 27.0929580519.

The spelling of 19887 in words is "nineteen thousand, eight hundred eighty-seven".