220561 has 4 divisors (see below), whose sum is σ = 240624. Its totient is φ = 200500.

The previous prime is 220559. The next prime is 220573. The reversal of 220561 is 165022.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 220561 - 2¹ = 220559 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10015 + ... + 10036.

It is an arithmetic number, because the mean of its divisors is an integer number (60156).

2²²⁰⁵⁶¹ is an apocalyptic number.

It is an amenable number.

220561 is a deficient number, since it is larger than the sum of its proper divisors (20063).

220561 is a wasteful number, since it uses less digits than its factorization.

220561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20062.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 220561 is about 469.6392232342. The cubic root of 220561 is about 60.4193767050.

Adding to 220561 its reverse (165022), we get a palindrome (385583).

The spelling of 220561 in words is "two hundred twenty thousand, five hundred sixty-one".