1183720561 has 2 divisors, whose sum is σ = 1183720562. Its totient is φ = 1183720560.

The previous prime is 1183720543. The next prime is 1183720567. The reversal of 1183720561 is 1650273811.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 860835600 + 322884961 = 29340^2 + 17969^2 .

It is a cyclic number.

It is not a de Polignac number, because 1183720561 - 2⁵ = 1183720529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1183720567) 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, 591860280 + 591860281.

It is an arithmetic number, because the mean of its divisors is an integer number (591860281).

Almost surely, 2^1183720561 is an apocalyptic number.

It is an amenable number.

1183720561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1183720561 is an equidigital number, since it uses as much as digits as its factorization.

1183720561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10080, while the sum is 34.

The square root of 1183720561 is about 34405.2403130686. The cubic root of 1183720561 is about 1057.8312609160.

The spelling of 1183720561 in words is "one billion, one hundred eighty-three million, seven hundred twenty thousand, five hundred sixty-one".