220918 has 4 divisors (see below), whose sum is σ = 331380. Its totient is φ = 110458.

The previous prime is 220907. The next prime is 220919. The reversal of 220918 is 819022.

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

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a plaindrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (220919) 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 as a sum of consecutive naturals, namely, 55228 + ... + 55231.

It is an arithmetic number, because the mean of its divisors is an integer number (82845).

2²²⁰⁹¹⁸ is an apocalyptic number.

220918 is a deficient number, since it is larger than the sum of its proper divisors (110462).

220918 is a wasteful number, since it uses less digits than its factorization.

220918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110461.

The product of its (nonzero) digits is 288, while the sum is 22.

The square root of 220918 is about 470.0191485461. The cubic root of 220918 is about 60.4519573975.

The spelling of 220918 in words is "two hundred twenty thousand, nine hundred eighteen".