1644428 has 24 divisors (see below), whose sum is σ = 3038784. Its totient is φ = 777600.

The previous prime is 1644421. The next prime is 1644437. The reversal of 1644428 is 8244461.

It is a Smith number, since the sum of its digits (29) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 1644428.

It is not an unprimeable number, because it can be changed into a prime (1644421) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5933 + ... + 6203.

It is an arithmetic number, because the mean of its divisors is an integer number (126616).

2^1644428 is an apocalyptic number.

It is an amenable number.

1644428 is a deficient number, since it is larger than the sum of its proper divisors (1394356).

1644428 is a wasteful number, since it uses less digits than its factorization.

1644428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 353 (or 351 counting only the distinct ones).

The product of its digits is 6144, while the sum is 29.

The square root of 1644428 is about 1282.3525256340. The cubic root of 1644428 is about 118.0334100550.

Adding to 1644428 its reverse (8244461), we get a palindrome (9888889).

It can be divided in two parts, 16 and 44428, that added together give a palindrome (44444).

The spelling of 1644428 in words is "one million, six hundred forty-four thousand, four hundred twenty-eight".