21381112771200 has 5184 divisors, whose sum is σ = 106226796049920. Its totient is φ = 4135886438400.

The previous prime is 21381112771189. The next prime is 21381112771267. The reversal of 21381112771200 is 217721118312.

It is a happy number.

21381112771200 is a `hidden beast` number, since 2 + 1 + 381 + 1 + 1 + 2 + 7 + 71 + 200 = 666.

It is a tau number, because it is divible by the number of its divisors (5184).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable 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 647 ways as a sum of consecutive naturals, for example, 689713315185 + ... + 689713315215.

Almost surely, 2^{21381112771200} is an apocalyptic number.

21381112771200 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 21381112771200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (53113398024960).

21381112771200 is an abundant number, since it is smaller than the sum of its proper divisors (84845683278720).

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

21381112771200 is an equidigital number, since it uses as much as digits as its factorization.

21381112771200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 137 (or 80 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 36.

Adding to 21381112771200 its reverse (217721118312), we get a palindrome (21598833889512).

The spelling of 21381112771200 in words is "twenty-one trillion, three hundred eighty-one billion, one hundred twelve million, seven hundred seventy-one thousand, two hundred".