3943861 has 4 divisors (see below), whose sum is σ = 3948300. Its totient is φ = 3939424.

The previous prime is 3943859. The next prime is 3943871. The reversal of 3943861 is 1683493.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 3294225 + 649636 = 1815^2 + 806^2 .

It is a cyclic number.

It is not a de Polignac number, because 3943861 - 2¹ = 3943859 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3943871) 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 in 3 ways as a sum of consecutive naturals, for example, 376 + ... + 2833.

It is an arithmetic number, because the mean of its divisors is an integer number (987075).

Almost surely, 2^3943861 is an apocalyptic number.

It is an amenable number.

3943861 is a deficient number, since it is larger than the sum of its proper divisors (4439).

3943861 is a wasteful number, since it uses less digits than its factorization.

3943861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4438.

The product of its digits is 15552, while the sum is 34.

The square root of 3943861 is about 1985.9156578264. The cubic root of 3943861 is about 157.9939777654.

The spelling of 3943861 in words is "three million, nine hundred forty-three thousand, eight hundred sixty-one".