3999891168 has 216 divisors, whose sum is σ = 14250265848. Its totient is φ = 1054867968.

The previous prime is 3999891167. The next prime is 3999891173. The reversal of 3999891168 is 8611989993.

3999891168 is a `hidden beast` number, since 399 + 9 + 89 + 1 + 168 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3999891163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 172555 + ... + 194357.

It is an arithmetic number, because the mean of its divisors is an integer number (65973453).

Almost surely, 2^3999891168 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 3999891168, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7125132924).

3999891168 is an abundant number, since it is smaller than the sum of its proper divisors (10250374680).

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

3999891168 is a wasteful number, since it uses less digits than its factorization.

3999891168 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21846 (or 21828 counting only the distinct ones).

The product of its digits is 7558272, while the sum is 63.

The square root of 3999891168 is about 63244.6928050093. The cubic root of 3999891168 is about 1587.3866551684.

The spelling of 3999891168 in words is "three billion, nine hundred ninety-nine million, eight hundred ninety-one thousand, one hundred sixty-eight".