221323320 has 128 divisors (see below), whose sum is σ = 745416000. Its totient is φ = 58406400.

The previous prime is 221323313. The next prime is 221323339. The reversal of 221323320 is 23323122.

It is a happy number.

221323320 is a `hidden beast` number, since 2 + 21 + 323 + 320 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 221323293 and 221323302.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 108066 + ... + 110094.

Almost surely, 2^221323320 is an apocalyptic number.

221323320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221323320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (372708000).

221323320 is an abundant number, since it is smaller than the sum of its proper divisors (524092680).

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

221323320 is a wasteful number, since it uses less digits than its factorization.

221323320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2150 (or 2140 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 221323320 is about 14876.9392013277. The cubic root of 221323320 is about 604.8890537171.

Adding to 221323320 its reverse (23323122), we get a palindrome (244646442).

It can be divided in two parts, 22132 and 3320, that added together give a palindrome (25452).

The spelling of 221323320 in words is "two hundred twenty-one million, three hundred twenty-three thousand, three hundred twenty".