2201665 has 4 divisors (see below), whose sum is σ = 2642004. Its totient is φ = 1761328.

The previous prime is 2201627. The next prime is 2201669. The reversal of 2201665 is 5661022.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5661022 = 2 ⋅2830511.

It can be written as a sum of positive squares in 2 ways, for example, as 1411344 + 790321 = 1188^2 + 889^2 .

It is a cyclic number.

It is not a de Polignac number, because 2201665 - 2²¹ = 104513 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2201669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 220162 + ... + 220171.

It is an arithmetic number, because the mean of its divisors is an integer number (660501).

2^2201665 is an apocalyptic number.

It is an amenable number.

2201665 is a deficient number, since it is larger than the sum of its proper divisors (440339).

2201665 is an equidigital number, since it uses as much as digits as its factorization.

2201665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440338.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 2201665 is about 1483.8008626497. The cubic root of 2201665 is about 130.0919467866.

Adding to 2201665 its reverse (5661022), we get a palindrome (7862687).

The spelling of 2201665 in words is "two million, two hundred one thousand, six hundred sixty-five".