819947 has 4 divisors (see below), whose sum is σ = 825600. Its totient is φ = 814296.

The previous prime is 819943. The next prime is 819977. The reversal of 819947 is 749918.

819947 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 819947 - 2² = 819943 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 819947.

It is not an unprimeable number, because it can be changed into a prime (819943) 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, 2603 + ... + 2900.

It is an arithmetic number, because the mean of its divisors is an integer number (206400).

2⁸¹⁹⁹⁴⁷ is an apocalyptic number.

819947 is a deficient number, since it is larger than the sum of its proper divisors (5653).

819947 is a wasteful number, since it uses less digits than its factorization.

819947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5652.

The product of its digits is 18144, while the sum is 38.

The square root of 819947 is about 905.5092489864. The cubic root of 819947 is about 93.5969996238.

The spelling of 819947 in words is "eight hundred nineteen thousand, nine hundred forty-seven".