3999989 has 16 divisors (see below), whose sum is σ = 4760448. Its totient is φ = 3290112.

The previous prime is 3999971. The next prime is 4000037. The reversal of 3999989 is 9899993.

It is a happy number.

3999989 is digitally balanced in base 8, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 3999989 - 2⁸ = 3999733 is a prime.

3999989 is strictly pandigital in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3999929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 29129 + ... + 29265.

It is an arithmetic number, because the mean of its divisors is an integer number (297528).

Almost surely, 2^3999989 is an apocalyptic number.

It is an amenable number.

3999989 is a deficient number, since it is larger than the sum of its proper divisors (760459).

3999989 is a wasteful number, since it uses less digits than its factorization.

3999989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284.

The product of its digits is 1417176, while the sum is 56.

The square root of 3999989 is about 1999.9972499981. The cubic root of 3999989 is about 158.7399596849.

The spelling of 3999989 in words is "three million, nine hundred ninety-nine thousand, nine hundred eighty-nine".