21212210223210 has 128 divisors (see below), whose sum is σ = 54188186443776. Its totient is φ = 5306123646720.

The previous prime is 21212210223161. The next prime is 21212210223271. The reversal of 21212210223210 is 1232201221212.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1498569 + ... + 6683571.

It is an arithmetic number, because the mean of its divisors is an integer number (423345206592).

Almost surely, 2^{21212210223210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21212210223210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27094093221888).

21212210223210 is an abundant number, since it is smaller than the sum of its proper divisors (32975976220566).

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

21212210223210 is a wasteful number, since it uses less digits than its factorization.

21212210223210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5185180.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21212210223210 its reverse (1232201221212), we get a palindrome (22444411444422).

The spelling of 21212210223210 in words is "twenty-one trillion, two hundred twelve billion, two hundred ten million, two hundred twenty-three thousand, two hundred ten".