221085 has 24 divisors (see below), whose sum is σ = 407160. Its totient is φ = 110976.

The previous prime is 221083. The next prime is 221087. The reversal of 221085 is 580122.

It is an interprime number because it is at equal distance from previous prime (221083) and next prime (221087).

It can be written as a sum of positive squares in 4 ways, for example, as 29241 + 191844 = 171^2 + 438^2 .

It is not a de Polignac number, because 221085 - 2¹ = 221083 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221083) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12997 + ... + 13013.

It is an arithmetic number, because the mean of its divisors is an integer number (16965).

2²²¹⁰⁸⁵ is an apocalyptic number.

It is an amenable number.

221085 is a deficient number, since it is larger than the sum of its proper divisors (186075).

221085 is an equidigital number, since it uses as much as digits as its factorization.

221085 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62 (or 25 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 221085 is about 470.1967673219. The cubic root of 221085 is about 60.4671861763.

The spelling of 221085 in words is "two hundred twenty-one thousand, eighty-five".