211211021210221 has 4 divisors (see below), whose sum is σ = 211212032186844. Its totient is φ = 211210010233600.

The previous prime is 211211021210183. The next prime is 211211021210237. The reversal of 211211021210221 is 122012120112112.

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 174662285952196 + 36548735258025 = 13215986^2 + 6045555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211211021210221 is a prime.

It is a super-2 number, since 2×211211021210221² (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 (211211021210251) 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, 505174870 + ... + 505592791.

It is an arithmetic number, because the mean of its divisors is an integer number (52803008046711).

Almost surely, 2^{211211021210221} is an apocalyptic number.

It is an amenable number.

211211021210221 is a deficient number, since it is larger than the sum of its proper divisors (1010976623).

211211021210221 is a wasteful number, since it uses less digits than its factorization.

211211021210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1010976622.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 211211021210221 its reverse (122012120112112), we get a palindrome (333223141322333).

The spelling of 211211021210221 in words is "two hundred eleven trillion, two hundred eleven billion, twenty-one million, two hundred ten thousand, two hundred twenty-one".