1668335091685 has 16 divisors (see below), whose sum is σ = 2079925277040. Its totient is φ = 1283114344960.

The previous prime is 1668335091551. The next prime is 1668335091721. The reversal of 1668335091685 is 5861905338661.

It can be written as a sum of positive squares in 8 ways, for example, as 212043672324 + 1456291419361 = 460482^2 + 1206769^2 .

It is not a de Polignac number, because 1668335091685 - 2¹⁵ = 1668335058917 is a prime.

It is a super-2 number, since 2×1668335091685² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24656686 + ... + 24724255.

It is an arithmetic number, because the mean of its divisors is an integer number (129995329815).

Almost surely, 2^{1668335091685} is an apocalyptic number.

It is an amenable number.

1668335091685 is a deficient number, since it is larger than the sum of its proper divisors (411590185355).

1668335091685 is a wasteful number, since it uses less digits than its factorization.

1668335091685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49381208.

The product of its (nonzero) digits is 27993600, while the sum is 61.

The spelling of 1668335091685 in words is "one trillion, six hundred sixty-eight billion, three hundred thirty-five million, ninety-one thousand, six hundred eighty-five".