281187668161 has 2 divisors, whose sum is σ = 281187668162. Its totient is φ = 281187668160.

The previous prime is 281187668143. The next prime is 281187668189. The reversal of 281187668161 is 161866781182.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 197874618561 + 83313049600 = 444831^2 + 288640^2 .

It is a cyclic number.

It is not a de Polignac number, because 281187668161 - 2¹¹ = 281187666113 is a prime.

It is not a weakly prime, because it can be changed into another prime (281187668191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 140593834080 + 140593834081.

It is an arithmetic number, because the mean of its divisors is an integer number (140593834081).

Almost surely, 2^281187668161 is an apocalyptic number.

It is an amenable number.

281187668161 is a deficient number, since it is larger than the sum of its proper divisors (1).

281187668161 is an equidigital number, since it uses as much as digits as its factorization.

281187668161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1548288, while the sum is 55.

The spelling of 281187668161 in words is "two hundred eighty-one billion, one hundred eighty-seven million, six hundred sixty-eight thousand, one hundred sixty-one".