1218172718089 has 2 divisors, whose sum is σ = 1218172718090. Its totient is φ = 1218172718088.

The previous prime is 1218172718051. The next prime is 1218172718111. The reversal of 1218172718089 is 9808172718121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 943928833600 + 274243884489 = 971560^2 + 523683^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218172718089 - 2¹⁹ = 1218172193801 is a prime.

It is not a weakly prime, because it can be changed into another prime (1218172718689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 609086359044 + 609086359045.

It is an arithmetic number, because the mean of its divisors is an integer number (609086359045).

Almost surely, 2^{1218172718089} is an apocalyptic number.

It is an amenable number.

1218172718089 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218172718089 is an equidigital number, since it uses as much as digits as its factorization.

1218172718089 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 903168, while the sum is 55.

The spelling of 1218172718089 in words is "one trillion, two hundred eighteen billion, one hundred seventy-two million, seven hundred eighteen thousand, eighty-nine".