1161323161 has 2 divisors, whose sum is σ = 1161323162. Its totient is φ = 1161323160.

The previous prime is 1161323129. The next prime is 1161323203. The reversal of 1161323161 is 1613231611.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1139467536 + 21855625 = 33756^2 + 4675^2 .

It is an emirp because it is prime and its reverse (1613231611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1161323161 - 2⁵ = 1161323129 is a prime.

It is not a weakly prime, because it can be changed into another prime (1161323101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 580661580 + 580661581.

It is an arithmetic number, because the mean of its divisors is an integer number (580661581).

Almost surely, 2^1161323161 is an apocalyptic number.

It is an amenable number.

1161323161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1161323161 is an equidigital number, since it uses as much as digits as its factorization.

1161323161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 648, while the sum is 25.

The square root of 1161323161 is about 34078.1918681141. The cubic root of 1161323161 is about 1051.1169251438.

Adding to 1161323161 its reverse (1613231611), we get a palindrome (2774554772).

The spelling of 1161323161 in words is "one billion, one hundred sixty-one million, three hundred twenty-three thousand, one hundred sixty-one".