21211101101021 has 16 divisors (see below), whose sum is σ = 24045191903040. Its totient is φ = 18548810161920.

The previous prime is 21211101101011. The next prime is 21211101101077. The reversal of 21211101101021 is 12010110111212.

It is a cyclic number.

It is not a de Polignac number, because 21211101101021 - 2¹⁰ = 21211101099997 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211101100987 and 21211101101005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211101101011) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 32306906 + ... + 32956916.

It is an arithmetic number, because the mean of its divisors is an integer number (1502824493940).

Almost surely, 2^{21211101101021} is an apocalyptic number.

It is an amenable number.

21211101101021 is a deficient number, since it is larger than the sum of its proper divisors (2834090802019).

21211101101021 is a wasteful number, since it uses less digits than its factorization.

21211101101021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782156.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 21211101101021 its reverse (12010110111212), we get a palindrome (33221211212233).

The spelling of 21211101101021 in words is "twenty-one trillion, two hundred eleven billion, one hundred one million, one hundred one thousand, twenty-one".