3989647 has 4 divisors (see below), whose sum is σ = 3993696. Its totient is φ = 3985600.

The previous prime is 3989641. The next prime is 3989651. The reversal of 3989647 is 7469893.

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, and also an emirpimes, since its reverse is a distinct semiprime: 7469893 = 37 ⋅201889.

It is a cyclic number.

It is not a de Polignac number, because 3989647 - 2⁷ = 3989519 is a prime.

It is a Duffinian number.

3989647 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 3989597 and 3989606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3989641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 522 + ... + 2872.

It is an arithmetic number, because the mean of its divisors is an integer number (998424).

Almost surely, 2^3989647 is an apocalyptic number.

3989647 is a deficient number, since it is larger than the sum of its proper divisors (4049).

3989647 is a wasteful number, since it uses less digits than its factorization.

3989647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4048.

The product of its digits is 326592, while the sum is 46.

The square root of 3989647 is about 1997.4100730696. The cubic root of 3989647 is about 158.6030338446.

The spelling of 3989647 in words is "three million, nine hundred eighty-nine thousand, six hundred forty-seven".