21081863880000 has 5040 divisors, whose sum is σ = 103719766550400. Its totient is φ = 4073287680000.

The previous prime is 21081863879987. The next prime is 21081863880019. The reversal of 21081863880000 is 8836818012.

21081863880000 is a `hidden beast` number, since 2 + 1 + 0 + 8 + 1 + 8 + 638 + 8 + 0 + 0 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (5040).

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 719 ways as a sum of consecutive naturals, for example, 253998359959 + ... + 253998360041.

It is an arithmetic number, because the mean of its divisors is an integer number (20579318760).

Almost surely, 2^{21081863880000} is an apocalyptic number.

21081863880000 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 21081863880000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51859883275200).

21081863880000 is an abundant number, since it is smaller than the sum of its proper divisors (82637902670400).

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

21081863880000 is a wasteful number, since it uses less digits than its factorization.

21081863880000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 128 counting only the distinct ones).

The product of its (nonzero) digits is 147456, while the sum is 45.

The spelling of 21081863880000 in words is "twenty-one trillion, eighty-one billion, eight hundred sixty-three million, eight hundred eighty thousand".