3981917 has 2 divisors, whose sum is σ = 3981918. Its totient is φ = 3981916.

The previous prime is 3981911. The next prime is 3981937. The reversal of 3981917 is 7191893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2515396 + 1466521 = 1586^2 + 1211^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3981917 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3981911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1990958 + 1990959.

It is an arithmetic number, because the mean of its divisors is an integer number (1990959).

Almost surely, 2^3981917 is an apocalyptic number.

It is an amenable number.

3981917 is a deficient number, since it is larger than the sum of its proper divisors (1).

3981917 is an equidigital number, since it uses as much as digits as its factorization.

3981917 is an evil number, because the sum of its binary digits is even.

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

The square root of 3981917 is about 1995.4741291232. The cubic root of 3981917 is about 158.5005357119.

The spelling of 3981917 in words is "three million, nine hundred eighty-one thousand, nine hundred seventeen".