3999920000 has 80 divisors (see below), whose sum is σ = 9957750000. Its totient is φ = 1599936000.

The previous prime is 3999919997. The next prime is 3999920027. The reversal of 3999920000 is 299993.

It is a tau number, because it is divible by the number of its divisors (80).

It is a self number, because there is not a number n which added to its sum of digits gives 3999920000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 55001 + ... + 104999.

It is an arithmetic number, because the mean of its divisors is an integer number (124471875).

Almost surely, 2^3999920000 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 3999920000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4978875000).

3999920000 is an abundant number, since it is smaller than the sum of its proper divisors (5957830000).

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

3999920000 is an frugal number, since it uses more digits than its factorization.

3999920000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50033 (or 50006 counting only the distinct ones).

The product of its (nonzero) digits is 39366, while the sum is 41.

The square root of 3999920000 is about 63244.9207446732. The cubic root of 3999920000 is about 1587.3904692240.

It can be divided in two parts, 39999 and 20000, that multiplied together give a triangular number (799980000 = T₃₉₉₉₉).

The spelling of 3999920000 in words is "three billion, nine hundred ninety-nine million, nine hundred twenty thousand".