1644404 has 6 divisors (see below), whose sum is σ = 2877714. Its totient is φ = 822200.

The previous prime is 1644373. The next prime is 1644413. The reversal of 1644404 is 4044461.

It can be written as a sum of positive squares in only one way, i.e., 1392400 + 252004 = 1180^2 + 502^2 .

It is a super-3 number, since 3×1644404³ = 13339723515237753792, which contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1644404.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 205547 + ... + 205554.

It is an arithmetic number, because the mean of its divisors is an integer number (479619).

2^1644404 is an apocalyptic number.

It is an amenable number.

1644404 is a deficient number, since it is larger than the sum of its proper divisors (1233310).

1644404 is a wasteful number, since it uses less digits than its factorization.

1644404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 411105 (or 411103 counting only the distinct ones).

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

The square root of 1644404 is about 1282.3431677987. The cubic root of 1644404 is about 118.0328358299.

Adding to 1644404 its reverse (4044461), we get a palindrome (5688865).

It can be divided in two parts, 1644 and 404, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 1644404 in words is "one million, six hundred forty-four thousand, four hundred four".