1644164444 has 12 divisors (see below), whose sum is σ = 3098617704. Its totient is φ = 758845104.

The previous prime is 1644164443. The next prime is 1644164497. The reversal of 1644164444 is 4444614461.

It is a super-3 number, since 3×1644164444³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1644164398 and 1644164407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1644164441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15809222 + ... + 15809325.

It is an arithmetic number, because the mean of its divisors is an integer number (258218142).

Almost surely, 2^1644164444 is an apocalyptic number.

It is an amenable number.

1644164444 is a deficient number, since it is larger than the sum of its proper divisors (1454453260).

1644164444 is a wasteful number, since it uses less digits than its factorization.

1644164444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31618564 (or 31618562 counting only the distinct ones).

The product of its digits is 147456, while the sum is 38.

The square root of 1644164444 is about 40548.2976708024. The cubic root of 1644164444 is about 1180.2710389553.

The spelling of 1644164444 in words is "one billion, six hundred forty-four million, one hundred sixty-four thousand, four hundred forty-four".