21210112221210 has 384 divisors, whose sum is σ = 61803385233408. Its totient is φ = 5002736256000.

The previous prime is 21210112221209. The next prime is 21210112221229. The reversal of 21210112221210 is 1212221101212.

21210112221210 is a `hidden beast` number, since 2 + 121 + 0 + 112 + 221 + 210 = 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 (19) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 6367489245 + ... + 6367492575.

It is an arithmetic number, because the mean of its divisors is an integer number (160946315712).

Almost surely, 2^{21210112221210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21210112221210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30901692616704).

21210112221210 is an abundant number, since it is smaller than the sum of its proper divisors (40593273012198).

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

21210112221210 is a wasteful number, since it uses less digits than its factorization.

21210112221210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4170 (or 4167 counting only the distinct ones).

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

Adding to 21210112221210 its reverse (1212221101212), we get a palindrome (22422333322422).

The spelling of 21210112221210 in words is "twenty-one trillion, two hundred ten billion, one hundred twelve million, two hundred twenty-one thousand, two hundred ten".