221366 has 8 divisors (see below), whose sum is σ = 334704. Its totient is φ = 109800.

The previous prime is 221327. The next prime is 221393. The reversal of 221366 is 663122.

221366 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 221366.

It is an unprimeable number.

221366 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 65 + ... + 668.

It is an arithmetic number, because the mean of its divisors is an integer number (41838).

2²²¹³⁶⁶ is an apocalyptic number.

221366 is a deficient number, since it is larger than the sum of its proper divisors (113338).

221366 is a wasteful number, since it uses less digits than its factorization.

221366 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886.

The product of its digits is 432, while the sum is 20.

The square root of 221366 is about 470.4954835065. The cubic root of 221366 is about 60.4927933496.

Adding to 221366 its reverse (663122), we get a palindrome (884488).

The spelling of 221366 in words is "two hundred twenty-one thousand, three hundred sixty-six".