21211221210102 has 192 divisors, whose sum is σ = 59321921218560. Its totient is φ = 5315094892800.

The previous prime is 21211221210031. The next prime is 21211221210169. The reversal of 21211221210102 is 20101212211212.

21211221210102 is a `hidden beast` number, since 21 + 211 + 221 + 210 + 1 + 0 + 2 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 49264468 + ... + 49693160.

It is an arithmetic number, because the mean of its divisors is an integer number (308968339680).

Almost surely, 2^{21211221210102} is an apocalyptic number.

21211221210102 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211221210102, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29660960609280).

21211221210102 is an abundant number, since it is smaller than the sum of its proper divisors (38110700008458).

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

21211221210102 is a wasteful number, since it uses less digits than its factorization.

21211221210102 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429979 (or 429976 counting only the distinct ones).

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

Adding to 21211221210102 its reverse (20101212211212), we get a palindrome (41312433421314).

The spelling of 21211221210102 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred ten thousand, one hundred two".