21010222211221 has 8 divisors (see below), whose sum is σ = 21960310665600. Its totient is φ = 20063183801232.

The previous prime is 21010222211207. The next prime is 21010222211249. The reversal of 21010222211221 is 12211222201012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21010222211221 - 2³⁷ = 20872783257749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010222211821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 762497010 + ... + 762524563.

It is an arithmetic number, because the mean of its divisors is an integer number (2745038833200).

Almost surely, 2^{21010222211221} is an apocalyptic number.

It is an amenable number.

21010222211221 is a deficient number, since it is larger than the sum of its proper divisors (950088454379).

21010222211221 is a wasteful number, since it uses less digits than its factorization.

21010222211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1525022195.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21010222211221 its reverse (12211222201012), we get a palindrome (33221444412233).

The spelling of 21010222211221 in words is "twenty-one trillion, ten billion, two hundred twenty-two million, two hundred eleven thousand, two hundred twenty-one".