20166161 has 2 divisors, whose sum is σ = 20166162. Its totient is φ = 20166160.

The previous prime is 20166143. The next prime is 20166169. The reversal of 20166161 is 16166102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16483600 + 3682561 = 4060^2 + 1919^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20166161 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20166169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10083080 + 10083081.

It is an arithmetic number, because the mean of its divisors is an integer number (10083081).

Almost surely, 2^20166161 is an apocalyptic number.

It is an amenable number.

20166161 is a deficient number, since it is larger than the sum of its proper divisors (1).

20166161 is an equidigital number, since it uses as much as digits as its factorization.

20166161 is an evil number, because the sum of its binary digits is even.

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

The square root of 20166161 is about 4490.6748935990. The cubic root of 20166161 is about 272.1914066897.

The spelling of 20166161 in words is "twenty million, one hundred sixty-six thousand, one hundred sixty-one".