2165555667 has 16 divisors (see below), whose sum is σ = 3164837760. Its totient is φ = 1306233600.

The previous prime is 2165555653. The next prime is 2165555677. The reversal of 2165555667 is 7665555612.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-2165555667 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2165555627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 148542 + ... + 162467.

It is an arithmetic number, because the mean of its divisors is an integer number (197802360).

Almost surely, 2^2165555667 is an apocalyptic number.

2165555667 is a deficient number, since it is larger than the sum of its proper divisors (999282093).

2165555667 is a wasteful number, since it uses less digits than its factorization.

2165555667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311234.

The product of its digits is 1890000, while the sum is 48.

The square root of 2165555667 is about 46535.5312315224. The cubic root of 2165555667 is about 1293.7681357209.

Subtracting 2165555667 from its reverse (7665555612), we obtain a palindrome (5499999945).

It can be divided in two parts, 216555 and 5667, that added together give a palindrome (222222).

The spelling of 2165555667 in words is "two billion, one hundred sixty-five million, five hundred fifty-five thousand, six hundred sixty-seven".