17881321121 has 2 divisors, whose sum is σ = 17881321122. Its totient is φ = 17881321120.

The previous prime is 17881321109. The next prime is 17881321151. The reversal of 17881321121 is 12112318871.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17878631521 + 2689600 = 133711^2 + 1640^2 .

It is an emirp because it is prime and its reverse (12112318871) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 17881321121 - 2⁶ = 17881321057 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (17881321151) 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, 8940660560 + 8940660561.

It is an arithmetic number, because the mean of its divisors is an integer number (8940660561).

Almost surely, 2^17881321121 is an apocalyptic number.

It is an amenable number.

17881321121 is a deficient number, since it is larger than the sum of its proper divisors (1).

17881321121 is an equidigital number, since it uses as much as digits as its factorization.

17881321121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5376, while the sum is 35.

Adding to 17881321121 its reverse (12112318871), we get a palindrome (29993639992).

The spelling of 17881321121 in words is "seventeen billion, eight hundred eighty-one million, three hundred twenty-one thousand, one hundred twenty-one".