3991424 has 16 divisors (see below), whose sum is σ = 7951920. Its totient is φ = 1995648.

The previous prime is 3991399. The next prime is 3991441. The reversal of 3991424 is 4241993.

It is a happy number.

3991424 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (16).

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a zygodrome in base 2.

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 as a sum of consecutive naturals, namely, 15464 + ... + 15719.

It is an arithmetic number, because the mean of its divisors is an integer number (496995).

Almost surely, 2^3991424 is an apocalyptic number.

It is an amenable number.

3991424 is a deficient number, since it is larger than the sum of its proper divisors (3960496).

3991424 is an equidigital number, since it uses as much as digits as its factorization.

3991424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31197 (or 31185 counting only the distinct ones).

The product of its digits is 7776, while the sum is 32.

The square root of 3991424 is about 1997.8548495824. The cubic root of 3991424 is about 158.6265777620.

The spelling of 3991424 in words is "three million, nine hundred ninety-one thousand, four hundred twenty-four".