2170643665 has 8 divisors (see below), whose sum is σ = 2675171880. Its totient is φ = 1689581952.

The previous prime is 2170643663. The next prime is 2170643681. The reversal of 2170643665 is 5663460712.

It can be written as a sum of positive squares in 4 ways, for example, as 1145619409 + 1025024256 = 33847^2 + 32016^2 .

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 2170643665 - 2¹ = 2170643663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2170643663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5866420 + ... + 5866789.

It is an arithmetic number, because the mean of its divisors is an integer number (334396485).

Almost surely, 2^2170643665 is an apocalyptic number.

It is an amenable number.

2170643665 is a deficient number, since it is larger than the sum of its proper divisors (504528215).

2170643665 is a wasteful number, since it uses less digits than its factorization.

2170643665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11733251.

The product of its (nonzero) digits is 181440, while the sum is 40.

The square root of 2170643665 is about 46590.1670419843. The cubic root of 2170643665 is about 1294.7805842636.

The spelling of 2170643665 in words is "two billion, one hundred seventy million, six hundred forty-three thousand, six hundred sixty-five".