221817243 has 8 divisors (see below), whose sum is σ = 301336848. Its totient is φ = 145087904.

The previous prime is 221817223. The next prime is 221817287. The reversal of 221817243 is 342718122.

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

It is a cyclic number.

It is not a de Polignac number, because 221817243 - 2¹⁰ = 221816219 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221817243.

It is not an unprimeable number, because it can be changed into a prime (221817203) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 697380 + ... + 697697.

It is an arithmetic number, because the mean of its divisors is an integer number (37667106).

Almost surely, 2^221817243 is an apocalyptic number.

221817243 is a deficient number, since it is larger than the sum of its proper divisors (79519605).

221817243 is a wasteful number, since it uses less digits than its factorization.

221817243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1395133.

The product of its digits is 5376, while the sum is 30.

The square root of 221817243 is about 14893.5302396712. The cubic root of 221817243 is about 605.3386924917.

The spelling of 221817243 in words is "two hundred twenty-one million, eight hundred seventeen thousand, two hundred forty-three".