3999864 has 64 divisors (see below), whose sum is σ = 11088000. Its totient is φ = 1192320.

The previous prime is 3999859. The next prime is 3999871. The reversal of 3999864 is 4689993.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28707 + ... + 28845.

It is an arithmetic number, because the mean of its divisors is an integer number (173250).

Almost surely, 2^3999864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3999864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (5544000).

3999864 is an abundant number, since it is smaller than the sum of its proper divisors (7088136).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3999864 is a wasteful number, since it uses less digits than its factorization.

3999864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268 (or 264 counting only the distinct ones).

The product of its digits is 419904, while the sum is 48.

The square root of 3999864 is about 1999.9659997110. The cubic root of 3999864 is about 158.7383061219.

The spelling of 3999864 in words is "three million, nine hundred ninety-nine thousand, eight hundred sixty-four".