820005 has 8 divisors (see below), whose sum is σ = 1312032. Its totient is φ = 437328.

The previous prime is 819991. The next prime is 820037. The reversal of 820005 is 500028.

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

It is not a de Polignac number, because 820005 - 2⁴ = 819989 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15), and also a Moran number because the ratio is a prime number: 54667 = 820005 / (8 + 2 + 0 + 0 + 0 + 5).

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 820005.

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, 27319 + ... + 27348.

It is an arithmetic number, because the mean of its divisors is an integer number (164004).

2⁸²⁰⁰⁰⁵ is an apocalyptic number.

It is an amenable number.

820005 is a deficient number, since it is larger than the sum of its proper divisors (492027).

820005 is a wasteful number, since it uses less digits than its factorization.

820005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54675.

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 820005 is about 905.5412745977. The cubic root of 820005 is about 93.5992064729.

The spelling of 820005 in words is "eight hundred twenty thousand, five".