221221332 has 72 divisors (see below), whose sum is σ = 607676160. Its totient is φ = 67599360.

The previous prime is 221221331. The next prime is 221221333. The reversal of 221221332 is 233122122.

221221332 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221221331) and next prime (221221333).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221221331) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15988 + ... + 26420.

Almost surely, 2^221221332 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221221332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (303838080).

221221332 is an abundant number, since it is smaller than the sum of its proper divisors (386454828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221221332 is a wasteful number, since it uses less digits than its factorization.

221221332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10493 (or 10488 counting only the distinct ones).

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

The square root of 221221332 is about 14873.5110851473. The cubic root of 221221332 is about 604.7961264659.

Adding to 221221332 its reverse (233122122), we get a palindrome (454343454).

The spelling of 221221332 in words is "two hundred twenty-one million, two hundred twenty-one thousand, three hundred thirty-two".