21112211212201 has 4 divisors (see below), whose sum is σ = 21112220548804. Its totient is φ = 21112201875600.

The previous prime is 21112211212187. The next prime is 21112211212231. The reversal of 21112211212201 is 10221211221112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 9882346704400 + 11229864507801 = 3143620^2 + 3351099^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21112211212201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21112211212231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1096471 + ... + 6589891.

It is an arithmetic number, because the mean of its divisors is an integer number (5278055137201).

Almost surely, 2^{21112211212201} is an apocalyptic number.

It is an amenable number.

21112211212201 is a deficient number, since it is larger than the sum of its proper divisors (9336603).

21112211212201 is an equidigital number, since it uses as much as digits as its factorization.

21112211212201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9336602.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 21112211212201 its reverse (10221211221112), we get a palindrome (31333422433313).

The spelling of 21112211212201 in words is "twenty-one trillion, one hundred twelve billion, two hundred eleven million, two hundred twelve thousand, two hundred one".