221504244 has 72 divisors (see below), whose sum is σ = 563230080. Its totient is φ = 67721472.

The previous prime is 221504221. The next prime is 221504251. The reversal of 221504244 is 442405122.

It is a happy number.

It is a super-2 number, since 2×221504244² = 98128260220023072, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 484464 + ... + 484920.

It is an arithmetic number, because the mean of its divisors is an integer number (7822640).

Almost surely, 2^221504244 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 221504244, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (281615040).

221504244 is an abundant number, since it is smaller than the sum of its proper divisors (341725836).

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

221504244 is a wasteful number, since it uses less digits than its factorization.

221504244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729 (or 714 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 24.

The square root of 221504244 is about 14883.0186454227. The cubic root of 221504244 is about 605.0538339729.

Adding to 221504244 its reverse (442405122), we get a palindrome (663909366).

The spelling of 221504244 in words is "two hundred twenty-one million, five hundred four thousand, two hundred forty-four".