6666858 has 36 divisors (see below), whose sum is σ = 15882594. Its totient is φ = 2019600.

The previous prime is 6666841. The next prime is 6666883. The reversal of 6666858 is 8586666.

It can be written as a sum of positive squares in only one way, i.e., 4052169 + 2614689 = 2013^2 + 1617^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 648 + ... + 3708.

Almost surely, 2^6666858 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6666858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7941297).

6666858 is an abundant number, since it is smaller than the sum of its proper divisors (9215736).

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

6666858 is a wasteful number, since it uses less digits than its factorization.

6666858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3091 (or 3077 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 6666858 is about 2582.0259487464. The cubic root of 6666858 is about 188.2090062746.

The spelling of 6666858 in words is "six million, six hundred sixty-six thousand, eight hundred fifty-eight".