1851666317 has 2 divisors, whose sum is σ = 1851666318. Its totient is φ = 1851666316.

The previous prime is 1851666293. The next prime is 1851666343. The reversal of 1851666317 is 7136661581.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 940894276 + 910772041 = 30674^2 + 30179^2 .

It is a cyclic number.

It is not a de Polignac number, because 1851666317 - 2⁶ = 1851666253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1851666917) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 925833158 + 925833159.

It is an arithmetic number, because the mean of its divisors is an integer number (925833159).

Almost surely, 2^1851666317 is an apocalyptic number.

It is an amenable number.

1851666317 is a deficient number, since it is larger than the sum of its proper divisors (1).

1851666317 is an equidigital number, since it uses as much as digits as its factorization.

1851666317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 181440, while the sum is 44.

The square root of 1851666317 is about 43030.9925170220. The cubic root of 1851666317 is about 1227.9694872028.

The spelling of 1851666317 in words is "one billion, eight hundred fifty-one million, six hundred sixty-six thousand, three hundred seventeen".