3999986 has 4 divisors (see below), whose sum is σ = 5999982. Its totient is φ = 1999992.

The previous prime is 3999971. The next prime is 4000037. The reversal of 3999986 is 6899993.

3999986 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 3924361 + 75625 = 1981^2 + 275^2 .

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 as a sum of consecutive naturals, namely, 999995 + ... + 999998.

Almost surely, 2^3999986 is an apocalyptic number.

3999986 is a deficient number, since it is larger than the sum of its proper divisors (1999996).

3999986 is a wasteful number, since it uses less digits than its factorization.

3999986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1999995.

The product of its digits is 944784, while the sum is 53.

The square root of 3999986 is about 1999.9964999969. The cubic root of 3999986 is about 158.7399199998.

It can be divided in two parts, 399998 and 6, that added together give a palindrome (400004).

The spelling of 3999986 in words is "three million, nine hundred ninety-nine thousand, nine hundred eighty-six".