3891971 has 2 divisors, whose sum is σ = 3891972. Its totient is φ = 3891970.

The previous prime is 3891917. The next prime is 3891977. The reversal of 3891971 is 1791983.

3891971 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (3891917) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3891971 - 2⁶ = 3891907 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3891977) 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, 1945985 + 1945986.

It is an arithmetic number, because the mean of its divisors is an integer number (1945986).

Almost surely, 2^3891971 is an apocalyptic number.

3891971 is a deficient number, since it is larger than the sum of its proper divisors (1).

3891971 is an equidigital number, since it uses as much as digits as its factorization.

3891971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13608, while the sum is 38.

The square root of 3891971 is about 1972.8078973889. The cubic root of 3891971 is about 157.2979992032.

The spelling of 3891971 in words is "three million, eight hundred ninety-one thousand, nine hundred seventy-one".