1668551717185 has 4 divisors (see below), whose sum is σ = 2002262060628. Its totient is φ = 1334841373744.

The previous prime is 1668551717149. The next prime is 1668551717197. The reversal of 1668551717185 is 5817171558661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 380798833921 + 1287752883264 = 617089^2 + 1134792^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668551717185 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 166855171714 + ... + 166855171723.

It is an arithmetic number, because the mean of its divisors is an integer number (500565515157).

Almost surely, 2^{1668551717185} is an apocalyptic number.

It is an amenable number.

1668551717185 is a deficient number, since it is larger than the sum of its proper divisors (333710343443).

1668551717185 is an equidigital number, since it uses as much as digits as its factorization.

1668551717185 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333710343442.

The product of its digits is 14112000, while the sum is 61.

The spelling of 1668551717185 in words is "one trillion, six hundred sixty-eight billion, five hundred fifty-one million, seven hundred seventeen thousand, one hundred eighty-five".