211020011221 has 4 divisors (see below), whose sum is σ = 211034939500. Its totient is φ = 211005082944.

The previous prime is 211020011207. The next prime is 211020011227. The reversal of 211020011221 is 122110020112.

211020011221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 98838556996 + 112181454225 = 314386^2 + 334935^2 .

It is a cyclic number.

It is not a de Polignac number, because 211020011221 - 2²¹ = 211017914069 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 (211020011227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7442916 + ... + 7471213.

It is an arithmetic number, because the mean of its divisors is an integer number (52758734875).

Almost surely, 2^211020011221 is an apocalyptic number.

It is an amenable number.

211020011221 is a deficient number, since it is larger than the sum of its proper divisors (14928279).

211020011221 is a wasteful number, since it uses less digits than its factorization.

211020011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14928278.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 211020011221 its reverse (122110020112), we get a palindrome (333130031333).

The spelling of 211020011221 in words is "two hundred eleven billion, twenty million, eleven thousand, two hundred twenty-one".