21022121220210 has 192 divisors, whose sum is σ = 61962814166400. Its totient is φ = 5067799608960.

The previous prime is 21022121220091. The next prime is 21022121220211. The reversal of 21022121220210 is 1202212122012.

It is a happy number.

21022121220210 is a `hidden beast` number, since 2 + 1 + 0 + 221 + 212 + 20 + 210 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21022121220211) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 4050532 + ... + 7645328.

It is an arithmetic number, because the mean of its divisors is an integer number (322722990450).

Almost surely, 2^{21022121220210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21022121220210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30981407083200).

21022121220210 is an abundant number, since it is smaller than the sum of its proper divisors (40940692946190).

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

21022121220210 is a wasteful number, since it uses less digits than its factorization.

21022121220210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3595014 (or 3594997 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21022121220210 its reverse (1202212122012), we get a palindrome (22224333342222).

The spelling of 21022121220210 in words is "twenty-one trillion, twenty-two billion, one hundred twenty-one million, two hundred twenty thousand, two hundred ten".