820065 has 16 divisors (see below), whose sum is σ = 1369728. Its totient is φ = 418176.

The previous prime is 820051. The next prime is 820067. The reversal of 820065 is 560028.

It is a happy number.

It is not a de Polignac number, because 820065 - 2⁷ = 819937 is a prime.

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (820067) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 844 + ... + 1533.

It is an arithmetic number, because the mean of its divisors is an integer number (85608).

2⁸²⁰⁰⁶⁵ is an apocalyptic number.

It is an amenable number.

820065 is a deficient number, since it is larger than the sum of its proper divisors (549663).

820065 is a wasteful number, since it uses less digits than its factorization.

820065 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2408.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 820065 is about 905.5744033485. The cubic root of 820065 is about 93.6014893108.

The spelling of 820065 in words is "eight hundred twenty thousand, sixty-five".