221644120 has 64 divisors (see below), whose sum is σ = 533952000. Its totient is φ = 82551168.

The previous prime is 221644117. The next prime is 221644121. The reversal of 221644120 is 21446122.

It is a happy number.

It is a super-2 number, since 2×221644120² = 98252231861148800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 221644091 and 221644100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221644121) 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, 42369 + ... + 47311.

It is an arithmetic number, because the mean of its divisors is an integer number (8343000).

Almost surely, 2^221644120 is an apocalyptic number.

221644120 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 221644120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (266976000).

221644120 is an abundant number, since it is smaller than the sum of its proper divisors (312307880).

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

221644120 is a wasteful number, since it uses less digits than its factorization.

221644120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5032 (or 5028 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 221644120 is about 14887.7170848992. The cubic root of 221644120 is about 605.1811674273.

The spelling of 221644120 in words is "two hundred twenty-one million, six hundred forty-four thousand, one hundred twenty".