1644228 has 18 divisors (see below), whose sum is σ = 4156334. Its totient is φ = 548064.

The previous prime is 1644221. The next prime is 1644229. The reversal of 1644228 is 8224461.

It can be written as a sum of positive squares in only one way, i.e., 1617984 + 26244 = 1272^2 + 162^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-3 number, since 3×1644228³ = 13335440735462821056, which contains 333 as substring.

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 5 ways as a sum of consecutive naturals, for example, 22801 + ... + 22872.

2^1644228 is an apocalyptic number.

1644228 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1644228 is an abundant number, since it is smaller than the sum of its proper divisors (2512106).

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

1644228 is a wasteful number, since it uses less digits than its factorization.

1644228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45683 (or 45678 counting only the distinct ones).

The product of its digits is 3072, while the sum is 27.

The square root of 1644228 is about 1282.2745415862. The cubic root of 1644228 is about 118.0286246749.

Adding to 1644228 its reverse (8224461), we get a palindrome (9868689).

It can be divided in two parts, 16 and 44228, that added together give a palindrome (44244).

The spelling of 1644228 in words is "one million, six hundred forty-four thousand, two hundred twenty-eight".