3981869 has 2 divisors, whose sum is σ = 3981870. Its totient is φ = 3981868.

The previous prime is 3981863. The next prime is 3981871. The reversal of 3981869 is 9681893.

3981869 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., 2449225 + 1532644 = 1565^2 + 1238^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3981869 is a prime.

It is a super-2 number, since 2×3981869² = 31710561466322, which contains 22 as substring.

Together with 3981871, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3981863) 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, 1990934 + 1990935.

It is an arithmetic number, because the mean of its divisors is an integer number (1990935).

Almost surely, 2^3981869 is an apocalyptic number.

It is an amenable number.

3981869 is a deficient number, since it is larger than the sum of its proper divisors (1).

3981869 is an equidigital number, since it uses as much as digits as its factorization.

3981869 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 44.

The square root of 3981869 is about 1995.4621018701. The cubic root of 3981869 is about 158.4998988280.

The spelling of 3981869 in words is "three million, nine hundred eighty-one thousand, eight hundred sixty-nine".