21121222112010 has 256 divisors, whose sum is σ = 59385814225920. Its totient is φ = 5331242188800.

The previous prime is 21121222111999. The next prime is 21121222112047. The reversal of 21121222112010 is 1021122212112.

21121222112010 is a `hidden beast` number, since 211 + 21 + 22 + 211 + 201 + 0 = 666.

It is a super-2 number, since 2×21121222112010² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 1325286762 + ... + 1325302698.

It is an arithmetic number, because the mean of its divisors is an integer number (231975836820).

Almost surely, 2^{21121222112010} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21121222112010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29692907112960).

21121222112010 is an abundant number, since it is smaller than the sum of its proper divisors (38264592113910).

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

21121222112010 is a wasteful number, since it uses less digits than its factorization.

21121222112010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18190 (or 18184 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21121222112010 its reverse (1021122212112), we get a palindrome (22142344324122).

The spelling of 21121222112010 in words is "twenty-one trillion, one hundred twenty-one billion, two hundred twenty-two million, one hundred twelve thousand, ten".