220081 has 4 divisors (see below), whose sum is σ = 227700. Its totient is φ = 212464.

The previous prime is 220063. The next prime is 220123. The reversal of 220081 is 180022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 180022 = 2 ⋅90011.

It can be written as a sum of positive squares in 2 ways, for example, as 43681 + 176400 = 209^2 + 420^2 .

It is a cyclic number.

It is not a de Polignac number, because 220081 - 2⁷ = 219953 is a prime.

It is a super-2 number, since 2×220081² = 96871293122, which contains 22 as substring.

It is a Duffinian number.

220081 is a lucky number.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (220021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3766 + ... + 3823.

It is an arithmetic number, because the mean of its divisors is an integer number (56925).

2²²⁰⁰⁸¹ is an apocalyptic number.

It is an amenable number.

220081 is a deficient number, since it is larger than the sum of its proper divisors (7619).

220081 is an equidigital number, since it uses as much as digits as its factorization.

220081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7618.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 220081 is about 469.1279143261. The cubic root of 220081 is about 60.3755152721.

The spelling of 220081 in words is "two hundred twenty thousand, eighty-one".