3991664 has 20 divisors (see below), whose sum is σ = 7768104. Its totient is φ = 1987008.

The previous prime is 3991649. The next prime is 3991667. The reversal of 3991664 is 4661993.

3991664 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 not an unprimeable number, because it can be changed into a prime (3991667) by changing a digit.

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, 4679 + ... + 5465.

Almost surely, 2^3991664 is an apocalyptic number.

It is an amenable number.

3991664 is a deficient number, since it is larger than the sum of its proper divisors (3776440).

3991664 is a wasteful number, since it uses less digits than its factorization.

3991664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1112 (or 1106 counting only the distinct ones).

The product of its digits is 34992, while the sum is 38.

The square root of 3991664 is about 1997.9149131032. The cubic root of 3991664 is about 158.6297570464.

The spelling of 3991664 in words is "three million, nine hundred ninety-one thousand, six hundred sixty-four".