1155595981 has 2 divisors, whose sum is σ = 1155595982. Its totient is φ = 1155595980.

The previous prime is 1155595957. The next prime is 1155595999. The reversal of 1155595981 is 1895955511.

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., 907816900 + 247779081 = 30130^2 + 15741^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155595981 - 2⁵ = 1155595949 is a prime.

It is a super-2 number, since 2×1155595981² = 2670804142606704722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1155595481) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 577797990 + 577797991.

It is an arithmetic number, because the mean of its divisors is an integer number (577797991).

Almost surely, 2^1155595981 is an apocalyptic number.

It is an amenable number.

1155595981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155595981 is an equidigital number, since it uses as much as digits as its factorization.

1155595981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 405000, while the sum is 49.

The square root of 1155595981 is about 33994.0580248961. The cubic root of 1155595981 is about 1049.3861812229.

The spelling of 1155595981 in words is "one billion, one hundred fifty-five million, five hundred ninety-five thousand, nine hundred eighty-one".