181369535993 has 2 divisors, whose sum is σ = 181369535994. Its totient is φ = 181369535992.

The previous prime is 181369535947. The next prime is 181369536017. The reversal of 181369535993 is 399535963181.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 149988122089 + 31381413904 = 387283^2 + 177148^2 .

It is a cyclic number.

It is not a de Polignac number, because 181369535993 - 2¹⁸ = 181369273849 is a prime.

It is a super-2 number, since 2×181369535993² (a number of 23 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (181369535923) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90684767996 + 90684767997.

It is an arithmetic number, because the mean of its divisors is an integer number (90684767997).

Almost surely, 2^181369535993 is an apocalyptic number.

It is an amenable number.

181369535993 is a deficient number, since it is larger than the sum of its proper divisors (1).

181369535993 is an equidigital number, since it uses as much as digits as its factorization.

181369535993 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23619600, while the sum is 62.

The spelling of 181369535993 in words is "one hundred eighty-one billion, three hundred sixty-nine million, five hundred thirty-five thousand, nine hundred ninety-three".