1868851718849 has 2 divisors, whose sum is σ = 1868851718850. Its totient is φ = 1868851718848.

The previous prime is 1868851718831. The next prime is 1868851718869. The reversal of 1868851718849 is 9488171588681.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1211690189824 + 657161529025 = 1100768^2 + 810655^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1868851718849 is a prime.

It is not a weakly prime, because it can be changed into another prime (1868851718869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 934425859424 + 934425859425.

It is an arithmetic number, because the mean of its divisors is an integer number (934425859425).

Almost surely, 2^{1868851718849} is an apocalyptic number.

It is an amenable number.

1868851718849 is a deficient number, since it is larger than the sum of its proper divisors (1).

1868851718849 is an equidigital number, since it uses as much as digits as its factorization.

1868851718849 is an evil number, because the sum of its binary digits is even.

The product of its digits is 247726080, while the sum is 74.

The spelling of 1868851718849 in words is "one trillion, eight hundred sixty-eight billion, eight hundred fifty-one million, seven hundred eighteen thousand, eight hundred forty-nine".