3981881 has 2 divisors, whose sum is σ = 3981882. Its totient is φ = 3981880.

The previous prime is 3981871. The next prime is 3981883. The reversal of 3981881 is 1881893.

3981881 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., 3367225 + 614656 = 1835^2 + 784^2 .

It is a cyclic number.

It is not a de Polignac number, because 3981881 - 2¹⁰ = 3980857 is a prime.

It is a super-2 number, since 2×3981881² = 31710752596322, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 3981883, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is equal to p₂₈₁₉₉₉ and since 3981881 and 281999 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (3981883) 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, 1990940 + 1990941.

It is an arithmetic number, because the mean of its divisors is an integer number (1990941).

Almost surely, 2^3981881 is an apocalyptic number.

It is an amenable number.

3981881 is a deficient number, since it is larger than the sum of its proper divisors (1).

3981881 is an equidigital number, since it uses as much as digits as its factorization.

3981881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 38.

The square root of 3981881 is about 1995.4651086902. The cubic root of 3981881 is about 158.5000580495.

The spelling of 3981881 in words is "three million, nine hundred eighty-one thousand, eight hundred eighty-one".