21084368991840 has 2304 divisors, whose sum is σ = 98004249907200. Its totient is φ = 3993698304000.

The previous prime is 21084368991839. The next prime is 21084368991901. The reversal of 21084368991840 is 4819986348012.

21084368991840 is a `hidden beast` number, since 2 + 1 + 0 + 8 + 4 + 368 + 99 + 184 + 0 = 666.

21084368991840 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 11515219725 + ... + 11515221555.

It is an arithmetic number, because the mean of its divisors is an integer number (42536566800).

Almost surely, 2^{21084368991840} is an apocalyptic number.

21084368991840 is a gapful number since it is divisible by the number (20) 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 21084368991840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49002124953600).

21084368991840 is an abundant number, since it is smaller than the sum of its proper divisors (76919880915360).

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

21084368991840 is a wasteful number, since it uses less digits than its factorization.

21084368991840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2077 (or 2066 counting only the distinct ones).

The product of its (nonzero) digits is 23887872, while the sum is 63.

The spelling of 21084368991840 in words is "twenty-one trillion, eighty-four billion, three hundred sixty-eight million, nine hundred ninety-one thousand, eight hundred forty".