3999939840 has 576 divisors, whose sum is σ = 15864710400. Its totient is φ = 947552256.

The previous prime is 3999939833. The next prime is 3999939949. The reversal of 3999939840 is 489399993.

It is a tau number, because it is divible by the number of its divisors (576).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 13028967 + ... + 13029273.

It is an arithmetic number, because the mean of its divisors is an integer number (27542900).

Almost surely, 2^3999939840 is an apocalyptic number.

3999939840 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 3999939840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7932355200).

3999939840 is an abundant number, since it is smaller than the sum of its proper divisors (11864770560).

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

3999939840 is a wasteful number, since it uses less digits than its factorization.

3999939840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 379 (or 359 counting only the distinct ones).

The product of its (nonzero) digits is 17006112, while the sum is 63.

The square root of 3999939840 is about 63245.0775950192. The cubic root of 3999939840 is about 1587.3930937577.

The spelling of 3999939840 in words is "three billion, nine hundred ninety-nine million, nine hundred thirty-nine thousand, eight hundred forty".