220445 has 4 divisors (see below), whose sum is σ = 264540. Its totient is φ = 176352.

The previous prime is 220421. The next prime is 220447. The reversal of 220445 is 544022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 544022 = 2 ⋅272011.

It can be written as a sum of positive squares in 2 ways, for example, as 89401 + 131044 = 299^2 + 362^2 .

It is a cyclic number.

It is not a de Polignac number, because 220445 - 2⁸ = 220189 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220447) 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, 22040 + ... + 22049.

It is an arithmetic number, because the mean of its divisors is an integer number (66135).

2²²⁰⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

220445 is a deficient number, since it is larger than the sum of its proper divisors (44095).

220445 is an equidigital number, since it uses as much as digits as its factorization.

220445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44094.

The product of its (nonzero) digits is 320, while the sum is 17.

The square root of 220445 is about 469.5157079374. The cubic root of 220445 is about 60.4087826943.

Adding to 220445 its reverse (544022), we get a palindrome (764467).

The spelling of 220445 in words is "two hundred twenty thousand, four hundred forty-five".