3991724 has 24 divisors (see below), whose sum is σ = 7671888. Its totient is φ = 1802240.

The previous prime is 3991723. The next prime is 3991727. The reversal of 3991724 is 4271993.

3991724 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is not an unprimeable number, because it can be changed into a prime (3991723) 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, 11132 + ... + 11484.

It is an arithmetic number, because the mean of its divisors is an integer number (319662).

Almost surely, 2^3991724 is an apocalyptic number.

It is an amenable number.

3991724 is a deficient number, since it is larger than the sum of its proper divisors (3680164).

3991724 is a wasteful number, since it uses less digits than its factorization.

3991724 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 625 (or 623 counting only the distinct ones).

The product of its digits is 13608, while the sum is 35.

The square root of 3991724 is about 1997.9299287012. The cubic root of 3991724 is about 158.6305518475.

The spelling of 3991724 in words is "three million, nine hundred ninety-one thousand, seven hundred twenty-four".