21111021220211 has 8 divisors (see below), whose sum is σ = 22900894441824. Its totient is φ = 19344854928960.

The previous prime is 21111021220199. The next prime is 21111021220229. The reversal of 21111021220211 is 11202212011112.

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

It is a cyclic number.

It is not a de Polignac number, because 21111021220211 - 2⁶ = 21111021220147 is a prime.

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 21111021220211.

It is not an unprimeable number, because it can be changed into a prime (21111021220291) 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, 5926730735 + ... + 5926734296.

It is an arithmetic number, because the mean of its divisors is an integer number (2862611805228).

Almost surely, 2^{21111021220211} is an apocalyptic number.

21111021220211 is a deficient number, since it is larger than the sum of its proper divisors (1789873221613).

21111021220211 is a wasteful number, since it uses less digits than its factorization.

21111021220211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11853465181.

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

Adding to 21111021220211 its reverse (11202212011112), we get a palindrome (32313233231323).

The spelling of 21111021220211 in words is "twenty-one trillion, one hundred eleven billion, twenty-one million, two hundred twenty thousand, two hundred eleven".