1183117561 has 2 divisors, whose sum is σ = 1183117562. Its totient is φ = 1183117560.

The previous prime is 1183117549. The next prime is 1183117577. The reversal of 1183117561 is 1657113811.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1069290000 + 113827561 = 32700^2 + 10669^2 .

It is a cyclic number.

It is not a de Polignac number, because 1183117561 - 2⁷ = 1183117433 is a prime.

It is not a weakly prime, because it can be changed into another prime (1183117531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 591558780 + 591558781.

It is an arithmetic number, because the mean of its divisors is an integer number (591558781).

Almost surely, 2^1183117561 is an apocalyptic number.

It is an amenable number.

1183117561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1183117561 is an equidigital number, since it uses as much as digits as its factorization.

1183117561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5040, while the sum is 34.

The square root of 1183117561 is about 34396.4759968227. The cubic root of 1183117561 is about 1057.6516068616.

It can be divided in two parts, 11831 and 17561, that added together give a palindrome (29392).

The spelling of 1183117561 in words is "one billion, one hundred eighty-three million, one hundred seventeen thousand, five hundred sixty-one".