21212011110001 has 4 divisors (see below), whose sum is σ = 21612237734772. Its totient is φ = 20811784485232.

The previous prime is 21212011109941. The next prime is 21212011110019. The reversal of 21212011110001 is 10001111021212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7294455680625 + 13917555429376 = 2700825^2 + 3730624^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212011110001 - 2⁹ = 21212011109489 is a prime.

It is a super-2 number, since 2×21212011110001² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212011110061) 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, 200113312306 + ... + 200113312411.

It is an arithmetic number, because the mean of its divisors is an integer number (5403059433693).

Almost surely, 2^{21212011110001} is an apocalyptic number.

It is an amenable number.

21212011110001 is a deficient number, since it is larger than the sum of its proper divisors (400226624771).

21212011110001 is an equidigital number, since it uses as much as digits as its factorization.

21212011110001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400226624770.

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

Adding to 21212011110001 its reverse (10001111021212), we get a palindrome (31213122131213).

The spelling of 21212011110001 in words is "twenty-one trillion, two hundred twelve billion, eleven million, one hundred ten thousand, one".