6444636985 has 8 divisors (see below), whose sum is σ = 7842488256. Its totient is φ = 5083093680.

The previous prime is 6444636977. The next prime is 6444637009. The reversal of 6444636985 is 5896364446.

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

It is not a de Polignac number, because 6444636985 - 2³ = 6444636977 is a prime.

It is a Duffinian 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, 9076599 + ... + 9077308.

It is an arithmetic number, because the mean of its divisors is an integer number (980311032).

Almost surely, 2^6444636985 is an apocalyptic number.

It is an amenable number.

6444636985 is a deficient number, since it is larger than the sum of its proper divisors (1397851271).

6444636985 is a wasteful number, since it uses less digits than its factorization.

6444636985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18153983.

The product of its digits is 14929920, while the sum is 55.

The square root of 6444636985 is about 80278.4964047035. The cubic root of 6444636985 is about 1860.9419232936.

The spelling of 6444636985 in words is "six billion, four hundred forty-four million, six hundred thirty-six thousand, nine hundred eighty-five".