220643 has 4 divisors (see below), whose sum is σ = 233640. Its totient is φ = 207648.

The previous prime is 220613. The next prime is 220663. The reversal of 220643 is 346022.

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

It is a cyclic number.

It is not a de Polignac number, because 220643 - 2⁶ = 220579 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 12979 = 220643 / (2 + 2 + 0 + 6 + 4 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (220613) 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, 6473 + ... + 6506.

It is an arithmetic number, because the mean of its divisors is an integer number (58410).

2²²⁰⁶⁴³ is an apocalyptic number.

220643 is a deficient number, since it is larger than the sum of its proper divisors (12997).

220643 is a wasteful number, since it uses less digits than its factorization.

220643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12996.

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 220643 is about 469.7265161772. The cubic root of 220643 is about 60.4268633338.

Adding to 220643 its reverse (346022), we get a palindrome (566665).

The spelling of 220643 in words is "two hundred twenty thousand, six hundred forty-three".