1187889845161 has 2 divisors, whose sum is σ = 1187889845162. Its totient is φ = 1187889845160.

The previous prime is 1187889845143. The next prime is 1187889845203. The reversal of 1187889845161 is 1615489887811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 825990145600 + 361899699561 = 908840^2 + 601581^2 .

It is a cyclic number.

It is not a de Polignac number, because 1187889845161 - 2¹⁹ = 1187889320873 is a prime.

It is a super-2 number, since 2×1187889845161² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1187889845861) 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, 593944922580 + 593944922581.

It is an arithmetic number, because the mean of its divisors is an integer number (593944922581).

Almost surely, 2^{1187889845161} is an apocalyptic number.

It is an amenable number.

1187889845161 is a deficient number, since it is larger than the sum of its proper divisors (1).

1187889845161 is an equidigital number, since it uses as much as digits as its factorization.

1187889845161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30965760, while the sum is 67.

The spelling of 1187889845161 in words is "one trillion, one hundred eighty-seven billion, eight hundred eighty-nine million, eight hundred forty-five thousand, one hundred sixty-one".