2163865 has 8 divisors (see below), whose sum is σ = 2832768. Its totient is φ = 1573680.

The previous prime is 2163859. The next prime is 2163869. The reversal of 2163865 is 5683612.

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

It is not a de Polignac number, because 2163865 - 2⁷ = 2163737 is a prime.

It is a d-powerful number, because it can be written as 2¹⁷ + 1 + 6³ + 3³ + 8⁵ + 6⁶ + 5⁹ .

It is a Duffinian number.

2163865 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2163869) 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 7 ways as a sum of consecutive naturals, for example, 19617 + ... + 19726.

It is an arithmetic number, because the mean of its divisors is an integer number (354096).

2^2163865 is an apocalyptic number.

It is an amenable number.

2163865 is a deficient number, since it is larger than the sum of its proper divisors (668903).

2163865 is a wasteful number, since it uses less digits than its factorization.

2163865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39359.

The product of its digits is 8640, while the sum is 31.

The square root of 2163865 is about 1471.0081576932. The cubic root of 2163865 is about 129.3431362948.

The spelling of 2163865 in words is "two million, one hundred sixty-three thousand, eight hundred sixty-five".