21212211012210 has 192 divisors, whose sum is σ = 57217571783424. Its totient is φ = 5447843136000.

The previous prime is 21212211012133. The next prime is 21212211012233. The reversal of 21212211012210 is 1221011221212.

21212211012210 is a `hidden beast` number, since 2 + 121 + 221 + 101 + 221 + 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 polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 2558458165 + ... + 2558466455.

It is an arithmetic number, because the mean of its divisors is an integer number (298008186372).

Almost surely, 2^{21212211012210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212211012210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28608785891712).

21212211012210 is an abundant number, since it is smaller than the sum of its proper divisors (36005360771214).

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

21212211012210 is a wasteful number, since it uses less digits than its factorization.

21212211012210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16049 (or 16046 counting only the distinct ones).

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

Adding to 21212211012210 its reverse (1221011221212), we get a palindrome (22433222233422).

The spelling of 21212211012210 in words is "twenty-one trillion, two hundred twelve billion, two hundred eleven million, twelve thousand, two hundred ten".