221232321 has 12 divisors (see below), whose sum is σ = 320126820. Its totient is φ = 147225600.

The previous prime is 221232283. The next prime is 221232343. The reversal of 221232321 is 123232122.

It can be written as a sum of positive squares in 2 ways, for example, as 92160000 + 129072321 = 9600^2 + 11361^2 .

It is not a de Polignac number, because 221232321 - 2¹⁴ = 221215937 is a prime.

It is a super-3 number, since 3×221232321³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221232294 and 221232303.

It is not an unprimeable number, because it can be changed into a prime (221232821) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16480 + ... + 26721.

It is an arithmetic number, because the mean of its divisors is an integer number (26677235).

Almost surely, 2^221232321 is an apocalyptic number.

It is an amenable number.

221232321 is a deficient number, since it is larger than the sum of its proper divisors (98894499).

221232321 is a wasteful number, since it uses less digits than its factorization.

221232321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43776 (or 43773 counting only the distinct ones).

The product of its digits is 288, while the sum is 18.

The square root of 221232321 is about 14873.8804956877. The cubic root of 221232321 is about 604.8061405613.

Adding to 221232321 its reverse (123232122), we get a palindrome (344464443).

The spelling of 221232321 in words is "two hundred twenty-one million, two hundred thirty-two thousand, three hundred twenty-one".