1181561141 has 2 divisors, whose sum is σ = 1181561142. Its totient is φ = 1181561140.

The previous prime is 1181561131. The next prime is 1181561167. The reversal of 1181561141 is 1411651811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 848498641 + 333062500 = 29129^2 + 18250^2 .

It is an emirp because it is prime and its reverse (1411651811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1181561141 - 2¹⁸ = 1181298997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1181561111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 590780570 + 590780571.

It is an arithmetic number, because the mean of its divisors is an integer number (590780571).

Almost surely, 2^1181561141 is an apocalyptic number.

It is an amenable number.

1181561141 is a deficient number, since it is larger than the sum of its proper divisors (1).

1181561141 is an equidigital number, since it uses as much as digits as its factorization.

1181561141 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 960, while the sum is 29.

The square root of 1181561141 is about 34373.8438496482. The cubic root of 1181561141 is about 1057.1876145117.

The spelling of 1181561141 in words is "one billion, one hundred eighty-one million, five hundred sixty-one thousand, one hundred forty-one".