211211002011221 has 4 divisors (see below), whose sum is σ = 211212811355244. Its totient is φ = 211209192667200.

The previous prime is 211211002011203. The next prime is 211211002011293. The reversal of 211211002011221 is 122110200112112.

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 151210331091121 + 60000670920100 = 12296761^2 + 7746010^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211211002011221 is a prime.

It is a super-2 number, since 2×211211002011221² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211211002011221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211002016221) 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, 904496900 + ... + 904730381.

It is an arithmetic number, because the mean of its divisors is an integer number (52803202838811).

Almost surely, 2^{211211002011221} is an apocalyptic number.

It is an amenable number.

211211002011221 is a deficient number, since it is larger than the sum of its proper divisors (1809344023).

211211002011221 is a wasteful number, since it uses less digits than its factorization.

211211002011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1809344022.

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

Adding to 211211002011221 its reverse (122110200112112), we get a palindrome (333321202123333).

The spelling of 211211002011221 in words is "two hundred eleven trillion, two hundred eleven billion, two million, eleven thousand, two hundred twenty-one".