3931861 has 2 divisors, whose sum is σ = 3931862. Its totient is φ = 3931860.

The previous prime is 3931847. The next prime is 3931891. The reversal of 3931861 is 1681393.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2992900 + 938961 = 1730^2 + 969^2 .

It is a cyclic number.

It is not a de Polignac number, because 3931861 - 2⁹ = 3931349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3931801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1965930 + 1965931.

It is an arithmetic number, because the mean of its divisors is an integer number (1965931).

Almost surely, 2^3931861 is an apocalyptic number.

It is an amenable number.

3931861 is a deficient number, since it is larger than the sum of its proper divisors (1).

3931861 is an equidigital number, since it uses as much as digits as its factorization.

3931861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 3931861 is about 1982.8920797663. The cubic root of 3931861 is about 157.8335720188.

The spelling of 3931861 in words is "three million, nine hundred thirty-one thousand, eight hundred sixty-one".