3937981 has 2 divisors, whose sum is σ = 3937982. Its totient is φ = 3937980.

The previous prime is 3937951. The next prime is 3937993. The reversal of 3937981 is 1897393.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3006756 + 931225 = 1734^2 + 965^2 .

It is a cyclic number.

It is not a de Polignac number, because 3937981 - 2⁵ = 3937949 is a prime.

It is a super-2 number, since 2×3937981² = 31015388712722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3937951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1968990 + 1968991.

It is an arithmetic number, because the mean of its divisors is an integer number (1968991).

Almost surely, 2^3937981 is an apocalyptic number.

It is an amenable number.

3937981 is a deficient number, since it is larger than the sum of its proper divisors (1).

3937981 is an equidigital number, since it uses as much as digits as its factorization.

3937981 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 40824, while the sum is 40.

The square root of 3937981 is about 1984.4346802049. The cubic root of 3937981 is about 157.9154196668.

The spelling of 3937981 in words is "three million, nine hundred thirty-seven thousand, nine hundred eighty-one".