221404440 has 128 divisors (see below), whose sum is σ = 701084160. Its totient is φ = 55824384.

The previous prime is 221404439. The next prime is 221404453. The reversal of 221404440 is 44404122.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 267307 + ... + 268133.

It is an arithmetic number, because the mean of its divisors is an integer number (5477220).

Almost surely, 2^221404440 is an apocalyptic number.

221404440 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 221404440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (350542080).

221404440 is an abundant number, since it is smaller than the sum of its proper divisors (479679720).

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

221404440 is a wasteful number, since it uses less digits than its factorization.

221404440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 961 (or 957 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 21.

The square root of 221404440 is about 14879.6653188168. The cubic root of 221404440 is about 604.9629465274.

Adding to 221404440 its reverse (44404122), we get a palindrome (265808562).

The spelling of 221404440 in words is "two hundred twenty-one million, four hundred four thousand, four hundred forty".