21011102012221 has 4 divisors (see below), whose sum is σ = 21011244988032. Its totient is φ = 21010959036412.

The previous prime is 21011102012171. The next prime is 21011102012233. The reversal of 21011102012221 is 12221020111012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21011102012221 - 2⁹ = 21011102011709 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21011102012195 and 21011102012204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21011102012321) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71267245 + ... + 71561458.

It is an arithmetic number, because the mean of its divisors is an integer number (5252811247008).

Almost surely, 2^{21011102012221} is an apocalyptic number.

It is an amenable number.

21011102012221 is a deficient number, since it is larger than the sum of its proper divisors (142975811).

21011102012221 is a wasteful number, since it uses less digits than its factorization.

21011102012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142975810.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21011102012221 its reverse (12221020111012), we get a palindrome (33232122123233).

The spelling of 21011102012221 in words is "twenty-one trillion, eleven billion, one hundred two million, twelve thousand, two hundred twenty-one".