3987644 has 24 divisors (see below), whose sum is σ = 7459200. Its totient is φ = 1859760.

The previous prime is 3987629. The next prime is 3987649. The reversal of 3987644 is 4467893.

It is a Smith number, since the sum of its digits (41) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3987649) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 5027 + ... + 5765.

It is an arithmetic number, because the mean of its divisors is an integer number (310800).

Almost surely, 2^3987644 is an apocalyptic number.

It is an amenable number.

3987644 is a deficient number, since it is larger than the sum of its proper divisors (3471556).

3987644 is a wasteful number, since it uses less digits than its factorization.

3987644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833 (or 831 counting only the distinct ones).

The product of its digits is 145152, while the sum is 41.

The square root of 3987644 is about 1996.9086108282. The cubic root of 3987644 is about 158.5764872140.

Subtracting 3987644 from its reverse (4467893), we obtain a square (480249 = 693²).

The spelling of 3987644 in words is "three million, nine hundred eighty-seven thousand, six hundred forty-four".