3947728 has 20 divisors (see below), whose sum is σ = 7687008. Its totient is φ = 1964000.

The previous prime is 3947693. The next prime is 3947747. The reversal of 3947728 is 8277493.

3947728 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 3525 + ... + 4507.

Almost surely, 2^3947728 is an apocalyptic number.

It is an amenable number.

3947728 is a deficient number, since it is larger than the sum of its proper divisors (3739280).

3947728 is a wasteful number, since it uses less digits than its factorization.

3947728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1242 (or 1236 counting only the distinct ones).

The product of its digits is 84672, while the sum is 40.

The square root of 3947728 is about 1986.8890255875. The cubic root of 3947728 is about 158.0455991871.

The spelling of 3947728 in words is "three million, nine hundred forty-seven thousand, seven hundred twenty-eight".