1851687878123 has 2 divisors, whose sum is σ = 1851687878124. Its totient is φ = 1851687878122.

The previous prime is 1851687878111. The next prime is 1851687878177. The reversal of 1851687878123 is 3218787861581.

It is a weak prime.

It is an emirp because it is prime and its reverse (3218787861581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1851687878123 - 2⁶ = 1851687878059 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1851687878123.

It is not a weakly prime, because it can be changed into another prime (1851687878323) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925843939061 + 925843939062.

It is an arithmetic number, because the mean of its divisors is an integer number (925843939062).

Almost surely, 2^{1851687878123} is an apocalyptic number.

1851687878123 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851687878123 is an equidigital number, since it uses as much as digits as its factorization.

1851687878123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36126720, while the sum is 65.

The spelling of 1851687878123 in words is "one trillion, eight hundred fifty-one billion, six hundred eighty-seven million, eight hundred seventy-eight thousand, one hundred twenty-three".