3991601 has 2 divisors, whose sum is σ = 3991602. Its totient is φ = 3991600.

The previous prime is 3991579. The next prime is 3991607. The reversal of 3991601 is 1061993.

3991601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3904576 + 87025 = 1976^2 + 295^2 .

It is an emirp because it is prime and its reverse (1061993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3991601 - 2¹⁴ = 3975217 is a prime.

It is not a weakly prime, because it can be changed into another prime (3991607) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995800 + 1995801.

It is an arithmetic number, because the mean of its divisors is an integer number (1995801).

Almost surely, 2^3991601 is an apocalyptic number.

It is an amenable number.

3991601 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991601 is an equidigital number, since it uses as much as digits as its factorization.

3991601 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1458, while the sum is 29.

The square root of 3991601 is about 1997.8991466038. The cubic root of 3991601 is about 158.6289224966.

The spelling of 3991601 in words is "three million, nine hundred ninety-one thousand, six hundred one".