181286521873 has 2 divisors, whose sum is σ = 181286521874. Its totient is φ = 181286521872.

The previous prime is 181286521837. The next prime is 181286521921. The reversal of 181286521873 is 378125682181.

Together with previous prime (181286521837) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 171237060864 + 10049461009 = 413808^2 + 100247^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-181286521873 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 181286521873.

It is not a weakly prime, because it can be changed into another prime (181286521673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 90643260936 + 90643260937.

It is an arithmetic number, because the mean of its divisors is an integer number (90643260937).

Almost surely, 2^181286521873 is an apocalyptic number.

It is an amenable number.

181286521873 is a deficient number, since it is larger than the sum of its proper divisors (1).

181286521873 is an equidigital number, since it uses as much as digits as its factorization.

181286521873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1290240, while the sum is 52.

The spelling of 181286521873 in words is "one hundred eighty-one billion, two hundred eighty-six million, five hundred twenty-one thousand, eight hundred seventy-three".