1644004 has 6 divisors (see below), whose sum is σ = 2877014. Its totient is φ = 822000.

The previous prime is 1644001. The next prime is 1644031. The reversal of 1644004 is 4004461.

It can be written as a sum of positive squares in only one way, i.e., 1004004 + 640000 = 1002^2 + 800^2 .

It is not an unprimeable number, because it can be changed into a prime (1644001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205497 + ... + 205504.

2^1644004 is an apocalyptic number.

It is an amenable number.

1644004 is a deficient number, since it is larger than the sum of its proper divisors (1233010).

1644004 is a wasteful number, since it uses less digits than its factorization.

1644004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411005 (or 411003 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 1644004 is about 1282.1871938216. The cubic root of 1644004 is about 118.0232645884.

Adding to 1644004 its reverse (4004461), we get a palindrome (5648465).

It can be divided in two parts, 164 and 4004, that multiplied together give a palindrome (656656).

The spelling of 1644004 in words is "one million, six hundred forty-four thousand, four".