3999006720 has 304 divisors, whose sum is σ = 14344492320. Its totient is φ = 1056964608.

The previous prime is 3999006673. The next prime is 3999006761. The reversal of 3999006720 is 276009993.

It is a Harshad number since it is a multiple of its sum of digits (45).

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, 35389384 + ... + 35389496.

It is an arithmetic number, because the mean of its divisors is an integer number (47185830).

Almost surely, 2^3999006720 is an apocalyptic number.

3999006720 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3999006720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7172246160).

3999006720 is an abundant number, since it is smaller than the sum of its proper divisors (10345485600).

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

3999006720 is an frugal number, since it uses more digits than its factorization.

3999006720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163 (or 123 counting only the distinct ones).

The product of its (nonzero) digits is 183708, while the sum is 45.

The square root of 3999006720 is about 63237.7001479339. The cubic root of 3999006720 is about 1587.2696466143.

The spelling of 3999006720 in words is "three billion, nine hundred ninety-nine million, six thousand, seven hundred twenty".