3989681 has 4 divisors (see below), whose sum is σ = 4065012. Its totient is φ = 3914352.

The previous prime is 3989663. The next prime is 3989683. The reversal of 3989681 is 1869893.

3989681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1869893 = 53 ⋅35281.

It can be written as a sum of positive squares in 2 ways, for example, as 3150625 + 839056 = 1775^2 + 916^2 .

It is a cyclic number.

It is not a de Polignac number, because 3989681 - 2¹⁴ = 3973297 is a prime.

It is a super-2 number, since 2×3989681² = 31835108963522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3989683) 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 in 3 ways as a sum of consecutive naturals, for example, 37586 + ... + 37691.

It is an arithmetic number, because the mean of its divisors is an integer number (1016253).

Almost surely, 2^3989681 is an apocalyptic number.

It is an amenable number.

3989681 is a deficient number, since it is larger than the sum of its proper divisors (75331).

3989681 is an equidigital number, since it uses as much as digits as its factorization.

3989681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 75330.

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

The square root of 3989681 is about 1997.4185840730. The cubic root of 3989681 is about 158.6034843847.

The spelling of 3989681 in words is "three million, nine hundred eighty-nine thousand, six hundred eighty-one".