820815 has 8 divisors (see below), whose sum is σ = 1313328. Its totient is φ = 437760.

The previous prime is 820793. The next prime is 820837. The reversal of 820815 is 518028.

820815 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (820793) and next prime (820837).

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

It is not a de Polignac number, because 820815 - 2⁸ = 820559 is a prime.

It is a congruent number.

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, 27346 + ... + 27375.

It is an arithmetic number, because the mean of its divisors is an integer number (164166).

2⁸²⁰⁸¹⁵ is an apocalyptic number.

820815 is a deficient number, since it is larger than the sum of its proper divisors (492513).

820815 is a wasteful number, since it uses less digits than its factorization.

820815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54729.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 820815 is about 905.9884105219. The cubic root of 820815 is about 93.6300153938.

The spelling of 820815 in words is "eight hundred twenty thousand, eight hundred fifteen".