1218161387 has 2 divisors, whose sum is σ = 1218161388. Its totient is φ = 1218161386.

The previous prime is 1218161339. The next prime is 1218161407. The reversal of 1218161387 is 7831618121.

It is a happy number.

It is a strong prime.

It is an emirp because it is prime and its reverse (7831618121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1218161387 - 2³⁰ = 144419563 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1218161387.

It is not a weakly prime, because it can be changed into another prime (1218160387) 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, 609080693 + 609080694.

It is an arithmetic number, because the mean of its divisors is an integer number (609080694).

Almost surely, 2^1218161387 is an apocalyptic number.

1218161387 is a deficient number, since it is larger than the sum of its proper divisors (1).

1218161387 is an equidigital number, since it uses as much as digits as its factorization.

1218161387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 16128, while the sum is 38.

The square root of 1218161387 is about 34902.1688008066. The cubic root of 1218161387 is about 1067.9926808567.

The spelling of 1218161387 in words is "one billion, two hundred eighteen million, one hundred sixty-one thousand, three hundred eighty-seven".