820165 has 8 divisors (see below), whose sum is σ = 1042200. Its totient is φ = 617472.

The previous prime is 820163. The next prime is 820177. The reversal of 820165 is 561028.

820165 = T₄₀₀ + T₄₀₁ + ... + T₄₀₉.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 47524 + 772641 = 218^2 + 879^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 820165 - 2¹ = 820163 is a prime.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4740 + ... + 4909.

It is an arithmetic number, because the mean of its divisors is an integer number (130275).

2⁸²⁰¹⁶⁵ is an apocalyptic number.

820165 is a gapful number since it is divisible by the number (85) formed by its first and last digit.

It is an amenable number.

820165 is a deficient number, since it is larger than the sum of its proper divisors (222035).

820165 is a wasteful number, since it uses less digits than its factorization.

820165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9671.

The product of its (nonzero) digits is 480, while the sum is 22.

The square root of 820165 is about 905.6296152401. The cubic root of 820165 is about 93.6052937932.

The spelling of 820165 in words is "eight hundred twenty thousand, one hundred sixty-five".