21221101101210 has 32 divisors (see below), whose sum is σ = 51030702881280. Its totient is φ = 5647842489408.

The previous prime is 21221101101197. The next prime is 21221101101227. The reversal of 21221101101210 is 1210110112212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21221101101210.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 694847242 + ... + 694877781.

It is an arithmetic number, because the mean of its divisors is an integer number (1594709465040).

Almost surely, 2^{21221101101210} is an apocalyptic number.

21221101101210 is an abundant number, since it is smaller than the sum of its proper divisors (29809601780070).

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

21221101101210 is a wasteful number, since it uses less digits than its factorization.

21221101101210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389725542.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21221101101210 its reverse (1210110112212), we get a palindrome (22431211213422).

The spelling of 21221101101210 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred one million, one hundred one thousand, two hundred ten".