221431321 has 8 divisors (see below), whose sum is σ = 225547200. Its totient is φ = 217343280.

The previous prime is 221431313. The next prime is 221431333. The reversal of 221431321 is 123134122.

It is a happy number.

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 221431321 - 2³ = 221431313 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221431351) 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, 9450 + ... + 23068.

It is an arithmetic number, because the mean of its divisors is an integer number (28193400).

Almost surely, 2^221431321 is an apocalyptic number.

It is an amenable number.

221431321 is a deficient number, since it is larger than the sum of its proper divisors (4115879).

221431321 is a wasteful number, since it uses less digits than its factorization.

221431321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13919.

The product of its digits is 288, while the sum is 19.

The square root of 221431321 is about 14880.5685711266. The cubic root of 221431321 is about 604.9874286485.

Adding to 221431321 its reverse (123134122), we get a palindrome (344565443).

The spelling of 221431321 in words is "two hundred twenty-one million, four hundred thirty-one thousand, three hundred twenty-one".