1685001851917 has 2 divisors, whose sum is σ = 1685001851918. Its totient is φ = 1685001851916.

The previous prime is 1685001851849. The next prime is 1685001851977. The reversal of 1685001851917 is 7191581005861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1031242281001 + 653759570916 = 1015501^2 + 808554^2 .

It is a cyclic number.

It is not a de Polignac number, because 1685001851917 - 2⁷ = 1685001851789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1685001851977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 842500925958 + 842500925959.

It is an arithmetic number, because the mean of its divisors is an integer number (842500925959).

Almost surely, 2^{1685001851917} is an apocalyptic number.

It is an amenable number.

1685001851917 is a deficient number, since it is larger than the sum of its proper divisors (1).

1685001851917 is an equidigital number, since it uses as much as digits as its factorization.

1685001851917 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 604800, while the sum is 52.

The spelling of 1685001851917 in words is "one trillion, six hundred eighty-five billion, one million, eight hundred fifty-one thousand, nine hundred seventeen".