19985 has 8 divisors (see below), whose sum is σ = 27456. Its totient is φ = 13680.

The previous prime is 19979. The next prime is 19991. The reversal of 19985 is 58991.

It is an interprime number because it is at equal distance from previous prime (19979) and next prime (19991).

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

It is not a de Polignac number, because 19985 - 2¹² = 15889 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 19985.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 251 + ... + 320.

It is an arithmetic number, because the mean of its divisors is an integer number (3432).

2¹⁹⁹⁸⁵ is an apocalyptic number.

It is an amenable number.

19985 is a deficient number, since it is larger than the sum of its proper divisors (7471).

19985 is an equidigital number, since it uses as much as digits as its factorization.

19985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 583.

The product of its digits is 3240, while the sum is 32.

The square root of 19985 is about 141.3683132813. The cubic root of 19985 is about 27.1373884247.

The spelling of 19985 in words is "nineteen thousand, nine hundred eighty-five".