6644165685 has 16 divisors (see below), whose sum is σ = 10645305216. Its totient is φ = 3538675008.

The previous prime is 6644165681. The next prime is 6644165753. The reversal of 6644165685 is 5865614466.

It is a happy number.

It is not a de Polignac number, because 6644165685 - 2² = 6644165681 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6644165681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 293734 + ... + 315543.

It is an arithmetic number, because the mean of its divisors is an integer number (665331576).

Almost surely, 2^6644165685 is an apocalyptic number.

It is an amenable number.

6644165685 is a deficient number, since it is larger than the sum of its proper divisors (4001139531).

6644165685 is a wasteful number, since it uses less digits than its factorization.

6644165685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 610012.

The product of its digits is 4147200, while the sum is 51.

The square root of 6644165685 is about 81511.7518214398. The cubic root of 6644165685 is about 1879.9522476365.

The spelling of 6644165685 in words is "six billion, six hundred forty-four million, one hundred sixty-five thousand, six hundred eighty-five".