3991825 has 6 divisors (see below), whose sum is σ = 4949894. Its totient is φ = 3193440.

The previous prime is 3991817. The next prime is 3991829. The reversal of 3991825 is 5281993.

3991825 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 59536 + 3932289 = 244^2 + 1983^2 .

It is not a de Polignac number, because 3991825 - 2³ = 3991817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3991829) 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 5 ways as a sum of consecutive naturals, for example, 79812 + ... + 79861.

Almost surely, 2^3991825 is an apocalyptic number.

It is an amenable number.

3991825 is a deficient number, since it is larger than the sum of its proper divisors (958069).

3991825 is a wasteful number, since it uses less digits than its factorization.

3991825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159683 (or 159678 counting only the distinct ones).

The product of its digits is 19440, while the sum is 37.

The square root of 3991825 is about 1997.9552047030. The cubic root of 3991825 is about 158.6318897449.

The spelling of 3991825 in words is "three million, nine hundred ninety-one thousand, eight hundred twenty-five".