3991736 has 48 divisors (see below), whose sum is σ = 9234000. Its totient is φ = 1607424.

The previous prime is 3991727. The next prime is 3991747. The reversal of 3991736 is 6371993.

It is a self number, because there is not a number n which added to its sum of digits gives 3991736.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6365 + ... + 6963.

It is an arithmetic number, because the mean of its divisors is an integer number (192375).

Almost surely, 2^3991736 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3991736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4617000).

3991736 is an abundant number, since it is smaller than the sum of its proper divisors (5242264).

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

3991736 is a wasteful number, since it uses less digits than its factorization.

3991736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 636 (or 625 counting only the distinct ones).

The product of its digits is 30618, while the sum is 38.

The square root of 3991736 is about 1997.9329318073. The cubic root of 3991736 is about 158.6307108068.

The spelling of 3991736 in words is "three million, nine hundred ninety-one thousand, seven hundred thirty-six".