1644055405 has 16 divisors (see below), whose sum is σ = 1982536704. Its totient is φ = 1308816000.

The previous prime is 1644055403. The next prime is 1644055417. The reversal of 1644055405 is 5045504461.

It is not a de Polignac number, because 1644055405 - 2¹ = 1644055403 is a prime.

It is a super-3 number, since 3×1644055405³ (a number of 29 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644055403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1377489 + ... + 1378681.

It is an arithmetic number, because the mean of its divisors is an integer number (123908544).

Almost surely, 2^1644055405 is an apocalyptic number.

It is an amenable number.

1644055405 is a deficient number, since it is larger than the sum of its proper divisors (338481299).

1644055405 is a wasteful number, since it uses less digits than its factorization.

1644055405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2316.

The product of its (nonzero) digits is 48000, while the sum is 34.

The square root of 1644055405 is about 40546.9530914470. The cubic root of 1644055405 is about 1180.2449469953.

Adding to 1644055405 its reverse (5045504461), we get a palindrome (6689559866).

The spelling of 1644055405 in words is "one billion, six hundred forty-four million, fifty-five thousand, four hundred five".