19847 has 4 divisors (see below), whose sum is σ = 20160. Its totient is φ = 19536.

The previous prime is 19843. The next prime is 19853. The reversal of 19847 is 74891.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 19847 - 2² = 19843 is a prime.

It is a Duffinian number.

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 19847.

It is not an unprimeable number, because it can be changed into a prime (19841) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23 + ... + 200.

It is an arithmetic number, because the mean of its divisors is an integer number (5040).

2¹⁹⁸⁴⁷ is an apocalyptic number.

19847 is a deficient number, since it is larger than the sum of its proper divisors (313).

19847 is an equidigital number, since it uses as much as digits as its factorization.

19847 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 312.

The product of its digits is 2016, while the sum is 29.

The square root of 19847 is about 140.8793810321. The cubic root of 19847 is about 27.0747812577.

It can be divided in two parts, 1984 and 7, that added together give a palindrome (1991).

The spelling of 19847 in words is "nineteen thousand, eight hundred forty-seven".