221133440 has 128 divisors (see below), whose sum is σ = 584288640. Its totient is φ = 79360000.

The previous prime is 221133427. The next prime is 221133443. The reversal of 221133440 is 44331122.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221133443) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 710885 + ... + 711195.

It is an arithmetic number, because the mean of its divisors is an integer number (4564755).

Almost surely, 2^221133440 is an apocalyptic number.

221133440 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 221133440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (292144320).

221133440 is an abundant number, since it is smaller than the sum of its proper divisors (363155200).

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

221133440 is a wasteful number, since it uses less digits than its factorization.

221133440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 430 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

The square root of 221133440 is about 14870.5561429289. The cubic root of 221133440 is about 604.7160199921.

Adding to 221133440 its reverse (44331122), we get a palindrome (265464562).

The spelling of 221133440 in words is "two hundred twenty-one million, one hundred thirty-three thousand, four hundred forty".