221121321 has 8 divisors (see below), whose sum is σ = 299825760. Its totient is φ = 144915552.

The previous prime is 221121293. The next prime is 221121343. The reversal of 221121321 is 123121122.

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

It is not a de Polignac number, because 221121321 - 2¹³ = 221113129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221121321.

It is not an unprimeable number, because it can be changed into a prime (221121391) 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, 624460 + ... + 624813.

It is an arithmetic number, because the mean of its divisors is an integer number (37478220).

Almost surely, 2^221121321 is an apocalyptic number.

It is an amenable number.

221121321 is a deficient number, since it is larger than the sum of its proper divisors (78704439).

221121321 is a wasteful number, since it uses less digits than its factorization.

221121321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1249335.

The product of its digits is 48, while the sum is 15.

The square root of 221121321 is about 14870.1486542670. The cubic root of 221121321 is about 604.7049728354.

Adding to 221121321 its reverse (123121122), we get a palindrome (344242443).

It can be divided in two parts, 2211 and 21321, that added together give a palindrome (23532).

The spelling of 221121321 in words is "two hundred twenty-one million, one hundred twenty-one thousand, three hundred twenty-one".