4471991665 has 4 divisors (see below), whose sum is σ = 5366390004. Its totient is φ = 3577593328.

The previous prime is 4471991663. The next prime is 4471991669. The reversal of 4471991665 is 5661991744.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3331713841 + 1140277824 = 57721^2 + 33768^2 .

It is a cyclic number.

It is not a de Polignac number, because 4471991665 - 2¹ = 4471991663 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (4471991663) 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, 447199162 + ... + 447199171.

It is an arithmetic number, because the mean of its divisors is an integer number (1341597501).

Almost surely, 2^4471991665 is an apocalyptic number.

It is an amenable number.

4471991665 is a deficient number, since it is larger than the sum of its proper divisors (894398339).

4471991665 is an equidigital number, since it uses as much as digits as its factorization.

4471991665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 894398338.

The product of its digits is 1632960, while the sum is 52.

The square root of 4471991665 is about 66872.9516695652. The cubic root of 4471991665 is about 1647.5312532881.

The spelling of 4471991665 in words is "four billion, four hundred seventy-one million, nine hundred ninety-one thousand, six hundred sixty-five".