1685166851873 has 2 divisors, whose sum is σ = 1685166851874. Its totient is φ = 1685166851872.

The previous prime is 1685166851833. The next prime is 1685166851911. The reversal of 1685166851873 is 3781586615861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1414213288849 + 270953563024 = 1189207^2 + 520532^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685166851873 - 2⁸ = 1685166851617 is a prime.

It is not a weakly prime, because it can be changed into another prime (1685166851833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842583425936 + 842583425937.

It is an arithmetic number, because the mean of its divisors is an integer number (842583425937).

Almost surely, 2^{1685166851873} is an apocalyptic number.

It is an amenable number.

1685166851873 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685166851873 is an equidigital number, since it uses as much as digits as its factorization.

1685166851873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 58060800, while the sum is 65.

The spelling of 1685166851873 in words is "one trillion, six hundred eighty-five billion, one hundred sixty-six million, eight hundred fifty-one thousand, eight hundred seventy-three".