9987991821084 has 96 divisors (see below), whose sum is σ = 24721006657536. Its totient is φ = 3127805107200.

The previous prime is 9987991821079. The next prime is 9987991821107. The reversal of 9987991821084 is 4801281997899.

9987991821084 = T₁ + T₂ + ... + T₃₉₁₃₂.

9987991821084 is a nontrivial binomial coefficient, being equal to C(39134, 3).

It is a junction number, because it is equal to n+sod(n) for n = 9987991820997 and 9987991821015.

It is a congruent number.

It is an unprimeable number.

It is the 39132-nd tetrahedral number.

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 31 ways as a sum of consecutive naturals, for example, 255212382 + ... + 255251514.

It is an arithmetic number, because the mean of its divisors is an integer number (257510486016).

Almost surely, 2^{9987991821084} is an apocalyptic number.

It is an amenable number.

9987991821084 is an abundant number, since it is smaller than the sum of its proper divisors (14733014836452).

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

9987991821084 is a wasteful number, since it uses less digits than its factorization.

9987991821084 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41395 (or 41393 counting only the distinct ones).

The product of its (nonzero) digits is 188116992, while the sum is 75.

The spelling of 9987991821084 in words is "nine trillion, nine hundred eighty-seven billion, nine hundred ninety-one million, eight hundred twenty-one thousand, eighty-four".