19685 has 8 divisors (see below), whose sum is σ = 24576. Its totient is φ = 15120.

The previous prime is 19681. The next prime is 19687. The reversal of 19685 is 58691.

19685 = T₁₉ + T₂₀ + ... + T₄₉.

19685 = 80² + 81² + 82².

19685 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 19685 - 2² = 19681 is a prime.

It is a Duffinian number.

19685 is strictly pandigital in base 6.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19681) 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, 92 + ... + 218.

It is an arithmetic number, because the mean of its divisors is an integer number (3072).

2¹⁹⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

19685 is a deficient number, since it is larger than the sum of its proper divisors (4891).

19685 is a wasteful number, since it uses less digits than its factorization.

19685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163.

The product of its digits is 2160, while the sum is 29.

The square root of 19685 is about 140.3032430131. The cubic root of 19685 is about 27.0009144638. Note that the first 3 decimals are identical.

The spelling of 19685 in words is "nineteen thousand, six hundred eighty-five".