1187129668181 has 2 divisors, whose sum is σ = 1187129668182. Its totient is φ = 1187129668180.

The previous prime is 1187129668163. The next prime is 1187129668189. The reversal of 1187129668181 is 1818669217811.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 778541522500 + 408588145681 = 882350^2 + 639209^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1187129668181 is a prime.

It is a super-2 number, since 2×1187129668181² (a number of 25 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1187129668181.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1187129668189) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 593564834090 + 593564834091.

It is an arithmetic number, because the mean of its divisors is an integer number (593564834091).

Almost surely, 2^{1187129668181} is an apocalyptic number.

It is an amenable number.

1187129668181 is a deficient number, since it is larger than the sum of its proper divisors (1).

1187129668181 is an equidigital number, since it uses as much as digits as its factorization.

1187129668181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2322432, while the sum is 59.

The spelling of 1187129668181 in words is "one trillion, one hundred eighty-seven billion, one hundred twenty-nine million, six hundred sixty-eight thousand, one hundred eighty-one".