3947561 has 2 divisors, whose sum is σ = 3947562. Its totient is φ = 3947560.

The previous prime is 3947557. The next prime is 3947569. The reversal of 3947561 is 1657493.

3947561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3610000 + 337561 = 1900^2 + 581^2 .

It is a cyclic number.

It is not a de Polignac number, because 3947561 - 2² = 3947557 is a prime.

It is not a weakly prime, because it can be changed into another prime (3947569) 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 as a sum of consecutive naturals, namely, 1973780 + 1973781.

It is an arithmetic number, because the mean of its divisors is an integer number (1973781).

Almost surely, 2^3947561 is an apocalyptic number.

It is an amenable number.

3947561 is a deficient number, since it is larger than the sum of its proper divisors (1).

3947561 is an equidigital number, since it uses as much as digits as its factorization.

3947561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 35.

The square root of 3947561 is about 1986.8469996454. The cubic root of 3947561 is about 158.0433705646.

The spelling of 3947561 in words is "three million, nine hundred forty-seven thousand, five hundred sixty-one".