1668686703605 has 16 divisors (see below), whose sum is σ = 2040530039280. Its totient is φ = 1309553376768.

The previous prime is 1668686703587. The next prime is 1668686703611. The reversal of 1668686703605 is 5063076868661.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 82882955236 + 1585803748369 = 287894^2 + 1259287^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1668686703605 is a prime.

It is a super-2 number, since 2×1668686703605² (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, 1179719 + ... + 2174651.

It is an arithmetic number, because the mean of its divisors is an integer number (127533127455).

Almost surely, 2^{1668686703605} is an apocalyptic number.

It is an amenable number.

1668686703605 is a deficient number, since it is larger than the sum of its proper divisors (371843335675).

1668686703605 is an equidigital number, since it uses as much as digits as its factorization.

1668686703605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1001320.

The product of its (nonzero) digits is 52254720, while the sum is 62.

The spelling of 1668686703605 in words is "one trillion, six hundred sixty-eight billion, six hundred eighty-six million, seven hundred three thousand, six hundred five".