3991804 has 24 divisors (see below), whose sum is σ = 7560000. Its totient is φ = 1837056.

The previous prime is 3991751. The next prime is 3991807. The reversal of 3991804 is 4081993.

It is a Harshad number since it is a multiple of its sum of digits (34).

It is a self number, because there is not a number n which added to its sum of digits gives 3991804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991807) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2572 + ... + 3820.

It is an arithmetic number, because the mean of its divisors is an integer number (315000).

Almost surely, 2^3991804 is an apocalyptic number.

3991804 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

It is an amenable number.

3991804 is a deficient number, since it is larger than the sum of its proper divisors (3568196).

3991804 is a wasteful number, since it uses less digits than its factorization.

3991804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1317 (or 1315 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 3991804 is about 1997.9499493231. The cubic root of 3991804 is about 158.6316115700.

The spelling of 3991804 in words is "three million, nine hundred ninety-one thousand, eight hundred four".