3991956820992 has 792 divisors, whose sum is σ = 13653987437376. Its totient is φ = 1100316672000.

The previous prime is 3991956820991. The next prime is 3991956820993. The reversal of 3991956820992 is 2990286591993.

3991956820992 is a `hidden beast` number, since 3 + 99 + 195 + 68 + 209 + 92 = 666.

It is an interprime number because it is at equal distance from previous prime (3991956820991) and next prime (3991956820993).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a self number, because there is not a number n which added to its sum of digits gives 3991956820992.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991956820991) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 14206251892 + ... + 14206252172.

It is an arithmetic number, because the mean of its divisors is an integer number (17239883128).

Almost surely, 2^{3991956820992} is an apocalyptic number.

3991956820992 is a gapful number since it is divisible by the number (32) 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 3991956820992, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6826993718688).

3991956820992 is an abundant number, since it is smaller than the sum of its proper divisors (9662030616384).

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

3991956820992 is a wasteful number, since it uses less digits than its factorization.

3991956820992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 527 (or 465 counting only the distinct ones).

The product of its (nonzero) digits is 170061120, while the sum is 72.

The spelling of 3991956820992 in words is "three trillion, nine hundred ninety-one billion, nine hundred fifty-six million, eight hundred twenty thousand, nine hundred ninety-two".