3999866 has 8 divisors (see below), whose sum is σ = 6461364. Its totient is φ = 1846080.

The previous prime is 3999859. The next prime is 3999871. The reversal of 3999866 is 6689993.

3999866 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 3530641 + 469225 = 1879^2 + 685^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76895 + ... + 76946.

Almost surely, 2^3999866 is an apocalyptic number.

3999866 is a deficient number, since it is larger than the sum of its proper divisors (2461498).

3999866 is a wasteful number, since it uses less digits than its factorization.

3999866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 153856.

The product of its digits is 629856, while the sum is 50.

The square root of 3999866 is about 1999.9664997194. The cubic root of 3999866 is about 158.7383325792.

The spelling of 3999866 in words is "three million, nine hundred ninety-nine thousand, eight hundred sixty-six".