21112100001000 has 192 divisors, whose sum is σ = 71387898454080. Its totient is φ = 5627605334400.

The previous prime is 21112100000977. The next prime is 21112100001007. The reversal of 21112100001000 is 10000121112.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (21112100001007) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 21727567 + ... + 22678433.

It is an arithmetic number, because the mean of its divisors is an integer number (371811971115).

Almost surely, 2^{21112100001000} is an apocalyptic number.

21112100001000 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 21112100001000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35693949227040).

21112100001000 is an abundant number, since it is smaller than the sum of its proper divisors (50275798453080).

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

21112100001000 is a wasteful number, since it uses less digits than its factorization.

21112100001000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 953361 (or 953344 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 9.

Adding to 21112100001000 its reverse (10000121112), we get a palindrome (21122100122112).

The spelling of 21112100001000 in words is "twenty-one trillion, one hundred twelve billion, one hundred million, one thousand".