1155181813 has 2 divisors, whose sum is σ = 1155181814. Its totient is φ = 1155181812.

The previous prime is 1155181801. The next prime is 1155181849. The reversal of 1155181813 is 3181815511.

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., 1154504484 + 677329 = 33978^2 + 823^2 .

It is a cyclic number.

It is not a de Polignac number, because 1155181813 - 2²¹ = 1153084661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1155181873) 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, 577590906 + 577590907.

It is an arithmetic number, because the mean of its divisors is an integer number (577590907).

Almost surely, 2^1155181813 is an apocalyptic number.

It is an amenable number.

1155181813 is a deficient number, since it is larger than the sum of its proper divisors (1).

1155181813 is an equidigital number, since it uses as much as digits as its factorization.

1155181813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4800, while the sum is 34.

The square root of 1155181813 is about 33987.9657084680. The cubic root of 1155181813 is about 1049.2607988469.

The spelling of 1155181813 in words is "one billion, one hundred fifty-five million, one hundred eighty-one thousand, eight hundred thirteen".