3989947 has 4 divisors (see below), whose sum is σ = 4296880. Its totient is φ = 3683016.

The previous prime is 3989941. The next prime is 3989957. The reversal of 3989947 is 7499893.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7499893 = 29 ⋅258617.

It is a cyclic number.

It is not a de Polignac number, because 3989947 - 2¹⁵ = 3957179 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3989947.

It is not an unprimeable number, because it can be changed into a prime (3989941) 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, 153447 + ... + 153472.

It is an arithmetic number, because the mean of its divisors is an integer number (1074220).

Almost surely, 2^3989947 is an apocalyptic number.

3989947 is a deficient number, since it is larger than the sum of its proper divisors (306933).

3989947 is a wasteful number, since it uses less digits than its factorization.

3989947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 306932.

The product of its digits is 489888, while the sum is 49.

The square root of 3989947 is about 1997.4851689061. The cubic root of 3989947 is about 158.6070091101.

The spelling of 3989947 in words is "three million, nine hundred eighty-nine thousand, nine hundred forty-seven".