21221112122010 has 128 divisors (see below), whose sum is σ = 57440041401600. Its totient is φ = 5574491193600.

The previous prime is 21221112121973. The next prime is 21221112122039. The reversal of 21221112122010 is 1022121112212.

21221112122010 is a `hidden beast` number, since 21 + 221 + 11 + 212 + 201 + 0 = 666.

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 63 ways as a sum of consecutive naturals, for example, 3397101 + ... + 7347279.

It is an arithmetic number, because the mean of its divisors is an integer number (448750323450).

Almost surely, 2^{21221112122010} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221112122010, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28720020700800).

21221112122010 is an abundant number, since it is smaller than the sum of its proper divisors (36218929279590).

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

21221112122010 is a wasteful number, since it uses less digits than its factorization.

21221112122010 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3950493 (or 3950487 counting only the distinct ones).

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

Adding to 21221112122010 its reverse (1022121112212), we get a palindrome (22243233234222).

The spelling of 21221112122010 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twelve million, one hundred twenty-two thousand, ten".