820105 has 32 divisors (see below), whose sum is σ = 1225728. Its totient is φ = 518400.

The previous prime is 820093. The next prime is 820109. The reversal of 820105 is 501028.

It is a happy number.

It is not a de Polignac number, because 820105 - 2⁵ = 820073 is a prime.

It is a super-2 number, since 2×820105² = 1345144422050, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (820109) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22147 + ... + 22183.

It is an arithmetic number, because the mean of its divisors is an integer number (38304).

2⁸²⁰¹⁰⁵ is an apocalyptic number.

It is an amenable number.

820105 is a deficient number, since it is larger than the sum of its proper divisors (405623).

820105 is a wasteful number, since it uses less digits than its factorization.

820105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 820105 is about 905.5964885091. The cubic root of 820105 is about 93.6030111409.

The spelling of 820105 in words is "eight hundred twenty thousand, one hundred five".