1644224 has 28 divisors (see below), whose sum is σ = 3407664. Its totient is φ = 785664.

The previous prime is 1644221. The next prime is 1644229. The reversal of 1644224 is 4224461.

It is a super-3 number, since 3×1644224³ = 13335343410213814272, which contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (23).

It is a self number, because there is not a number n which added to its sum of digits gives 1644224.

It is not an unprimeable number, because it can be changed into a prime (1644221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 914 + ... + 2030.

2^1644224 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 1644224, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1703832).

1644224 is an abundant number, since it is smaller than the sum of its proper divisors (1763440).

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

1644224 is a wasteful number, since it uses less digits than its factorization.

1644224 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1152 (or 1142 counting only the distinct ones).

The product of its digits is 1536, while the sum is 23.

The square root of 1644224 is about 1282.2729818568. The cubic root of 1644224 is about 118.0285289633.

Adding to 1644224 its reverse (4224461), we get a palindrome (5868685).

The spelling of 1644224 in words is "one million, six hundred forty-four thousand, two hundred twenty-four".