2166161 has 2 divisors, whose sum is σ = 2166162. Its totient is φ = 2166160.

The previous prime is 2166137. The next prime is 2166167. The reversal of 2166161 is 1616612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2119936 + 46225 = 1456^2 + 215^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2166161 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2166167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1083080 + 1083081.

It is an arithmetic number, because the mean of its divisors is an integer number (1083081).

2^2166161 is an apocalyptic number.

It is an amenable number.

2166161 is a deficient number, since it is larger than the sum of its proper divisors (1).

2166161 is an equidigital number, since it uses as much as digits as its factorization.

2166161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 23.

The square root of 2166161 is about 1471.7883679388. The cubic root of 2166161 is about 129.3888672542.

The spelling of 2166161 in words is "two million, one hundred sixty-six thousand, one hundred sixty-one".