21101112201221 has 8 divisors (see below), whose sum is σ = 22724778961920. Its totient is φ = 19477517481072.

The previous prime is 21101112201181. The next prime is 21101112201233. The reversal of 21101112201221 is 12210221110112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21101112201221 is a prime.

It is a super-2 number, since 2×21101112201221² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21101112201221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101112201271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17401025 + ... + 18574118.

It is an arithmetic number, because the mean of its divisors is an integer number (2840597370240).

Almost surely, 2^{21101112201221} is an apocalyptic number.

It is an amenable number.

21101112201221 is a deficient number, since it is larger than the sum of its proper divisors (1623666760699).

21101112201221 is a wasteful number, since it uses less digits than its factorization.

21101112201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36020275.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 21101112201221 its reverse (12210221110112), we get a palindrome (33311333311333).

The spelling of 21101112201221 in words is "twenty-one trillion, one hundred one billion, one hundred twelve million, two hundred one thousand, two hundred twenty-one".