17987 has 2 divisors, whose sum is σ = 17988. Its totient is φ = 17986.

The previous prime is 17981. The next prime is 17989. The reversal of 17987 is 78971.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 17987 - 2⁴ = 17971 is a prime.

Together with 17989, it forms a pair of twin primes.

It is a Chen prime.

It is a plaindrome in base 14.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 17987.

It is not a weakly prime, because it can be changed into another prime (17981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8993 + 8994.

It is an arithmetic number, because the mean of its divisors is an integer number (8994).

2¹⁷⁹⁸⁷ is an apocalyptic number.

17987 is a deficient number, since it is larger than the sum of its proper divisors (1).

17987 is an equidigital number, since it uses as much as digits as its factorization.

17987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3528, while the sum is 32.

The square root of 17987 is about 134.1156217597. The cubic root of 17987 is about 26.2011032304.

Subtracting from 17987 its sum of digits (32), we obtain a triangular number (17955 = T₁₈₉).

The spelling of 17987 in words is "seventeen thousand, nine hundred eighty-seven".