3989991 has 8 divisors (see below), whose sum is σ = 5332864. Its totient is φ = 2653560.

The previous prime is 3989989. The next prime is 3990001. The reversal of 3989991 is 1999893.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 3989991 - 2¹ = 3989989 is a prime.

It is a Duffinian number.

It is a zygodrome in base 2.

It is a self number, because there is not a number n which added to its sum of digits gives 3989991.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 96 + ... + 2826.

It is an arithmetic number, because the mean of its divisors is an integer number (666608).

Almost surely, 2^3989991 is an apocalyptic number.

3989991 is a deficient number, since it is larger than the sum of its proper divisors (1342873).

3989991 is a wasteful number, since it uses less digits than its factorization.

3989991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3221.

The product of its digits is 157464, while the sum is 48.

The square root of 3989991 is about 1997.4961827248. The cubic root of 3989991 is about 158.6075921323.

The spelling of 3989991 in words is "three million, nine hundred eighty-nine thousand, nine hundred ninety-one".