220621 has 4 divisors (see below), whose sum is σ = 226044. Its totient is φ = 215200.

The previous prime is 220613. The next prime is 220663. The reversal of 220621 is 126022.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 35721 + 184900 = 189^2 + 430^2 .

It is a cyclic number.

It is not a de Polignac number, because 220621 - 2³ = 220613 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220681) 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, 2650 + ... + 2731.

It is an arithmetic number, because the mean of its divisors is an integer number (56511).

2²²⁰⁶²¹ is an apocalyptic number.

It is an amenable number.

220621 is a deficient number, since it is larger than the sum of its proper divisors (5423).

220621 is an equidigital number, since it uses as much as digits as its factorization.

220621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5422.

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 220621 is about 469.7030977117. The cubic root of 220621 is about 60.4248549082.

Adding to 220621 its reverse (126022), we get a palindrome (346643).

It can be divided in two parts, 220 and 621, that added together give a square (841 = 29²).

The spelling of 220621 in words is "two hundred twenty thousand, six hundred twenty-one".