221321322 has 80 divisors (see below), whose sum is σ = 511612200. Its totient is φ = 71480448.

The previous prime is 221321297. The next prime is 221321323. The reversal of 221321322 is 223123122.

221321322 is a `hidden beast` number, since 2 + 21 + 321 + 322 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 207100881 + 14220441 = 14391^2 + 3771^2 .

It is a super-5 number, since 5×221321322⁵ (a number of 43 digits) contains 55555 as substring.

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 junction number, because it is equal to n+sod(n) for n = 221321295 and 221321304.

It is not an unprimeable number, because it can be changed into a prime (221321323) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1279228 + ... + 1279400.

Almost surely, 2^221321322 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221321322, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (255806100).

221321322 is an abundant number, since it is smaller than the sum of its proper divisors (290290878).

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

221321322 is a wasteful number, since it uses less digits than its factorization.

221321322 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389 (or 380 counting only the distinct ones).

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

The square root of 221321322 is about 14876.8720502665. The cubic root of 221321322 is about 604.8872334962.

Adding to 221321322 its reverse (223123122), we get a palindrome (444444444).

The spelling of 221321322 in words is "two hundred twenty-one million, three hundred twenty-one thousand, three hundred twenty-two".