221420321 has 8 divisors (see below), whose sum is σ = 234741504. Its totient is φ = 208485360.

The previous prime is 221420293. The next prime is 221420323. The reversal of 221420321 is 123024122.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221420321 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221420321.

It is not an unprimeable number, because it can be changed into a prime (221420323) 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 in 7 ways as a sum of consecutive naturals, for example, 95375 + ... + 97668.

It is an arithmetic number, because the mean of its divisors is an integer number (29342688).

Almost surely, 2^221420321 is an apocalyptic number.

It is an amenable number.

221420321 is a deficient number, since it is larger than the sum of its proper divisors (13321183).

221420321 is a wasteful number, since it uses less digits than its factorization.

221420321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193111.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 221420321 is about 14880.1989570032. The cubic root of 221420321 is about 604.9774105356.

Adding to 221420321 its reverse (123024122), we get a palindrome (344444443).

The spelling of 221420321 in words is "two hundred twenty-one million, four hundred twenty thousand, three hundred twenty-one".