6858687666 has 16 divisors (see below), whose sum is σ = 13725857088. Its totient is φ = 2284815600.

The previous prime is 6858687631. The next prime is 6858687707. The reversal of 6858687666 is 6667868586.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 6858687597 and 6858687606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 342870 + ... + 362321.

It is an arithmetic number, because the mean of its divisors is an integer number (857866068).

Almost surely, 2^6858687666 is an apocalyptic number.

6858687666 is an abundant number, since it is smaller than the sum of its proper divisors (6867169422).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6858687666 is a wasteful number, since it uses less digits than its factorization.

6858687666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 706817.

The product of its digits is 139345920, while the sum is 66.

The square root of 6858687666 is about 82817.1942654422. The cubic root of 6858687666 is about 1899.9711598577.

The spelling of 6858687666 in words is "six billion, eight hundred fifty-eight million, six hundred eighty-seven thousand, six hundred sixty-six".