3991664160 has 432 divisors, whose sum is σ = 15476348160. Its totient is φ = 935193600.

The previous prime is 3991664143. The next prime is 3991664161. The reversal of 3991664160 is 614661993.

3991664160 is a `hidden beast` number, since 399 + 166 + 41 + 60 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (3991664161) 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 71 ways as a sum of consecutive naturals, for example, 5401071 + ... + 5401809.

It is an arithmetic number, because the mean of its divisors is an integer number (35824880).

Almost surely, 2^3991664160 is an apocalyptic number.

3991664160 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 3991664160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7738174080).

3991664160 is an abundant number, since it is smaller than the sum of its proper divisors (11484684000).

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

3991664160 is a wasteful number, since it uses less digits than its factorization.

3991664160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813 (or 791 counting only the distinct ones).

The product of its (nonzero) digits is 209952, while the sum is 45.

The square root of 3991664160 is about 63179.6182324648. The cubic root of 3991664160 is about 1586.2975916584.

The spelling of 3991664160 in words is "three billion, nine hundred ninety-one million, six hundred sixty-four thousand, one hundred sixty".