211211012210021 has 4 divisors (see below), whose sum is σ = 211211673388044. Its totient is φ = 211210351032000.

The previous prime is 211211012209987. The next prime is 211211012210111. The reversal of 211211012210021 is 120012210112112.

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 21498569589025 + 189712442620996 = 4636655^2 + 13773614^2 .

It is a cyclic number.

It is not a de Polignac number, because 211211012210021 - 2¹⁰ = 211211012208997 is a prime.

It is a super-2 number, since 2×211211012210021² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211012710021) 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, 330109610 + ... + 330748811.

It is an arithmetic number, because the mean of its divisors is an integer number (52802918347011).

Almost surely, 2^{211211012210021} is an apocalyptic number.

It is an amenable number.

211211012210021 is a deficient number, since it is larger than the sum of its proper divisors (661178023).

211211012210021 is an equidigital number, since it uses as much as digits as its factorization.

211211012210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661178022.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 211211012210021 its reverse (120012210112112), we get a palindrome (331223222322133).

The spelling of 211211012210021 in words is "two hundred eleven trillion, two hundred eleven billion, twelve million, two hundred ten thousand, twenty-one".