20109161 has 2 divisors, whose sum is σ = 20109162. Its totient is φ = 20109160.

The previous prime is 20109139. The next prime is 20109191. The reversal of 20109161 is 16190102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14440000 + 5669161 = 3800^2 + 2381^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20109161 is a prime.

It is a super-2 number, since 2×20109161² = 808756712247842, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20109191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10054580 + 10054581.

It is an arithmetic number, because the mean of its divisors is an integer number (10054581).

Almost surely, 2^20109161 is an apocalyptic number.

It is an amenable number.

20109161 is a deficient number, since it is larger than the sum of its proper divisors (1).

20109161 is an equidigital number, since it uses as much as digits as its factorization.

20109161 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 20109161 is about 4484.3239178275. The cubic root of 20109161 is about 271.9347134615.

Adding to 20109161 its reverse (16190102), we get a palindrome (36299263).

The spelling of 20109161 in words is "twenty million, one hundred nine thousand, one hundred sixty-one".