2165312065 has 16 divisors (see below), whose sum is σ = 2989244160. Its totient is φ = 1474948800.

The previous prime is 2165311997. The next prime is 2165312077. The reversal of 2165312065 is 5602135612.

It is not a de Polignac number, because 2165312065 - 2¹⁹ = 2164787777 is a prime.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 199570 + ... + 210139.

It is an arithmetic number, because the mean of its divisors is an integer number (186827760).

Almost surely, 2^2165312065 is an apocalyptic number.

It is an amenable number.

2165312065 is a deficient number, since it is larger than the sum of its proper divisors (823932095).

2165312065 is a wasteful number, since it uses less digits than its factorization.

2165312065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409872.

The product of its (nonzero) digits is 10800, while the sum is 31.

The square root of 2165312065 is about 46532.9137815375. The cubic root of 2165312065 is about 1293.7196221795.

Adding to 2165312065 its reverse (5602135612), we get a palindrome (7767447677).

The spelling of 2165312065 in words is "two billion, one hundred sixty-five million, three hundred twelve thousand, sixty-five".