1018173061861 has 2 divisors, whose sum is σ = 1018173061862. Its totient is φ = 1018173061860.

The previous prime is 1018173061817. The next prime is 1018173061909. The reversal of 1018173061861 is 1681603718101.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 831716640225 + 186456421636 = 911985^2 + 431806^2 .

It is an emirp because it is prime and its reverse (1681603718101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1018173061861 - 2⁷ = 1018173061733 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1018173011861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 509086530930 + 509086530931.

It is an arithmetic number, because the mean of its divisors is an integer number (509086530931).

Almost surely, 2^{1018173061861} is an apocalyptic number.

It is an amenable number.

1018173061861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1018173061861 is an equidigital number, since it uses as much as digits as its factorization.

1018173061861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 48384, while the sum is 43.

Adding to 1018173061861 its reverse (1681603718101), we get a palindrome (2699776779962).

The spelling of 1018173061861 in words is "one trillion, eighteen billion, one hundred seventy-three million, sixty-one thousand, eight hundred sixty-one".