820385 has 8 divisors (see below), whose sum is σ = 1005696. Its totient is φ = 642160.

The previous prime is 820367. The next prime is 820399. The reversal of 820385 is 583028.

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

It is not a de Polignac number, because 820385 - 2⁶ = 820321 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1511 + ... + 1980.

It is an arithmetic number, because the mean of its divisors is an integer number (125712).

2⁸²⁰³⁸⁵ is an apocalyptic number.

It is an amenable number.

820385 is a deficient number, since it is larger than the sum of its proper divisors (185311).

820385 is a wasteful number, since it uses less digits than its factorization.

820385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3543.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 820385 is about 905.7510695550. The cubic root of 820385 is about 93.6136625660.

The spelling of 820385 in words is "eight hundred twenty thousand, three hundred eighty-five".