3989666 has 4 divisors (see below), whose sum is σ = 5984502. Its totient is φ = 1994832.

The previous prime is 3989663. The next prime is 3989683. The reversal of 3989666 is 6669893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6669893 = 19 ⋅351047.

It can be written as a sum of positive squares in only one way, i.e., 2088025 + 1901641 = 1445^2 + 1379^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 3989666.

It is not an unprimeable number, because it can be changed into a prime (3989663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 997415 + ... + 997418.

Almost surely, 2^3989666 is an apocalyptic number.

3989666 is a deficient number, since it is larger than the sum of its proper divisors (1994836).

3989666 is a wasteful number, since it uses less digits than its factorization.

3989666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1994835.

The product of its digits is 419904, while the sum is 47.

The square root of 3989666 is about 1997.4148292230. The cubic root of 3989666 is about 158.6032856174.

The spelling of 3989666 in words is "three million, nine hundred eighty-nine thousand, six hundred sixty-six".