1644244685 has 8 divisors (see below), whose sum is σ = 1973790720. Its totient is φ = 1314931024.

The previous prime is 1644244669. The next prime is 1644244699. The reversal of 1644244685 is 5864424461.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1644244685 - 2⁴ = 1644244669 is a prime.

It is a super-3 number, since 3×1644244685³ (a number of 29 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42125 + ... + 71154.

It is an arithmetic number, because the mean of its divisors is an integer number (246723840).

Almost surely, 2^1644244685 is an apocalyptic number.

It is an amenable number.

1644244685 is a deficient number, since it is larger than the sum of its proper divisors (329546035).

1644244685 is a wasteful number, since it uses less digits than its factorization.

1644244685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116187.

The product of its digits is 737280, while the sum is 44.

The square root of 1644244685 is about 40549.2871084067. The cubic root of 1644244685 is about 1180.2902391005.

The spelling of 1644244685 in words is "one billion, six hundred forty-four million, two hundred forty-four thousand, six hundred eighty-five".