3987866 has 4 divisors (see below), whose sum is σ = 5981802. Its totient is φ = 1993932.

The previous prime is 3987859. The next prime is 3987887. The reversal of 3987866 is 6687893.

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., 3045025 + 942841 = 1745^2 + 971^2 .

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 3987866.

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 as a sum of consecutive naturals, namely, 996965 + ... + 996968.

Almost surely, 2^3987866 is an apocalyptic number.

3987866 is a deficient number, since it is larger than the sum of its proper divisors (1993936).

3987866 is a wasteful number, since it uses less digits than its factorization.

3987866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1993935.

The product of its digits is 435456, while the sum is 47.

The square root of 3987866 is about 1996.9641959735. The cubic root of 3987866 is about 158.5794299146.

The spelling of 3987866 in words is "three million, nine hundred eighty-seven thousand, eight hundred sixty-six".