211001200021 has 4 divisors (see below), whose sum is σ = 218277103500. Its totient is φ = 203725296544.

The previous prime is 211001200009. The next prime is 211001200027. The reversal of 211001200021 is 120002100112.

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 76568977521 + 134432222500 = 276711^2 + 366650^2 .

It is a cyclic number.

It is not a de Polignac number, because 211001200021 - 2⁹ = 211001199509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211001199980 and 211001200007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211001200027) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3637951696 + ... + 3637951753.

It is an arithmetic number, because the mean of its divisors is an integer number (54569275875).

Almost surely, 2^211001200021 is an apocalyptic number.

It is an amenable number.

211001200021 is a deficient number, since it is larger than the sum of its proper divisors (7275903479).

211001200021 is an equidigital number, since it uses as much as digits as its factorization.

211001200021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7275903478.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 211001200021 its reverse (120002100112), we get a palindrome (331003300133).

Subtracting from 211001200021 its reverse (120002100112), we obtain a palindrome (90999099909).

The spelling of 211001200021 in words is "two hundred eleven billion, one million, two hundred thousand, twenty-one".