21001110211201 has 4 divisors (see below), whose sum is σ = 21001119378004. Its totient is φ = 21001101044400.

The previous prime is 21001110211181. The next prime is 21001110211267. The reversal of 21001110211201 is 10211201110012.

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 9073342815601 + 11927767395600 = 3012199^2 + 3453660^2 .

It is a cyclic number.

It is not a de Polignac number, because 21001110211201 - 2¹⁷ = 21001110080129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21001110211001) 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, 2171191 + ... + 6834931.

It is an arithmetic number, because the mean of its divisors is an integer number (5250279844501).

Almost surely, 2^{21001110211201} is an apocalyptic number.

It is an amenable number.

21001110211201 is a deficient number, since it is larger than the sum of its proper divisors (9166803).

21001110211201 is an equidigital number, since it uses as much as digits as its factorization.

21001110211201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9166802.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 21001110211201 its reverse (10211201110012), we get a palindrome (31212311321213).

The spelling of 21001110211201 in words is "twenty-one trillion, one billion, one hundred ten million, two hundred eleven thousand, two hundred one".