2165081 has 2 divisors, whose sum is σ = 2165082. Its totient is φ = 2165080.

The previous prime is 2165077. The next prime is 2165083. The reversal of 2165081 is 1805612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1175056 + 990025 = 1084^2 + 995^2 .

It is a cyclic number.

It is not a de Polignac number, because 2165081 - 2² = 2165077 is a prime.

It is a super-2 number, since 2×2165081² = 9375151473122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 2165083, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (2165083) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1082540 + 1082541.

It is an arithmetic number, because the mean of its divisors is an integer number (1082541).

2^2165081 is an apocalyptic number.

It is an amenable number.

2165081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2165081 is an equidigital number, since it uses as much as digits as its factorization.

2165081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 480, while the sum is 23.

The square root of 2165081 is about 1471.4214216192. The cubic root of 2165081 is about 129.3673602029.

The spelling of 2165081 in words is "two million, one hundred sixty-five thousand, eighty-one".