21012220111111 has 8 divisors (see below), whose sum is σ = 21284144418240. Its totient is φ = 20741092069632.

The previous prime is 21012220111007. The next prime is 21012220111151. The reversal of 21012220111111 is 11111102221012.

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 21012220111111 - 2¹³ = 21012220102919 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 (21012220111151) 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, 199013295 + ... + 199118848.

It is an arithmetic number, because the mean of its divisors is an integer number (2660518052280).

Almost surely, 2^{21012220111111} is an apocalyptic number.

21012220111111 is a deficient number, since it is larger than the sum of its proper divisors (271924307129).

21012220111111 is an equidigital number, since it uses as much as digits as its factorization.

21012220111111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398132825.

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

Adding to 21012220111111 its reverse (11111102221012), we get a palindrome (32123322332123).

The spelling of 21012220111111 in words is "twenty-one trillion, twelve billion, two hundred twenty million, one hundred eleven thousand, one hundred eleven".