581811161 has 2 divisors, whose sum is σ = 581811162. Its totient is φ = 581811160.

The previous prime is 581811143. The next prime is 581811163. The reversal of 581811161 is 161118185.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 295152400 + 286658761 = 17180^2 + 16931^2 .

It is a cyclic number.

It is not a de Polignac number, because 581811161 - 2²² = 577616857 is a prime.

It is a Sophie Germain prime.

Together with 581811163, 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 (581811163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 290905580 + 290905581.

It is an arithmetic number, because the mean of its divisors is an integer number (290905581).

Almost surely, 2^581811161 is an apocalyptic number.

It is an amenable number.

581811161 is a deficient number, since it is larger than the sum of its proper divisors (1).

581811161 is an equidigital number, since it uses as much as digits as its factorization.

581811161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1920, while the sum is 32.

The square root of 581811161 is about 24120.7620319094. The cubic root of 581811161 is about 834.8222510002.

The spelling of 581811161 in words is "five hundred eighty-one million, eight hundred eleven thousand, one hundred sixty-one".