3991992 has 32 divisors (see below), whose sum is σ = 10195200. Its totient is φ = 1301984.

The previous prime is 3991973. The next prime is 3991993. The reversal of 3991992 is 2991993.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991993) 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, 642 + ... + 2897.

It is an arithmetic number, because the mean of its divisors is an integer number (318600).

Almost surely, 2^3991992 is an apocalyptic number.

It is an amenable number.

3991992 is an abundant number, since it is smaller than the sum of its proper divisors (6203208).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3991992 is a wasteful number, since it uses less digits than its factorization.

3991992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3595 (or 3591 counting only the distinct ones).

The product of its digits is 39366, while the sum is 42.

The square root of 3991992 is about 1997.9969969947. The cubic root of 3991992 is about 158.6341018622.

Subtracting from 3991992 its reverse (2991993), we obtain a palindrome (999999).

The spelling of 3991992 in words is "three million, nine hundred ninety-one thousand, nine hundred ninety-two".