211220221211 has 4 divisors (see below), whose sum is σ = 211941109632. Its totient is φ = 210499332792.

The previous prime is 211220221189. The next prime is 211220221259. The reversal of 211220221211 is 112122022112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 211220221211 - 2¹⁰ = 211220220187 is a prime.

It is a super-2 number, since 2×211220221211² (a number of 23 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 211220221211.

It is not an unprimeable number, because it can be changed into a prime (211220221111) 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, 360443771 + ... + 360444356.

It is an arithmetic number, because the mean of its divisors is an integer number (52985277408).

Almost surely, 2^211220221211 is an apocalyptic number.

211220221211 is a deficient number, since it is larger than the sum of its proper divisors (720888421).

211220221211 is an equidigital number, since it uses as much as digits as its factorization.

211220221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 720888420.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 211220221211 its reverse (112122022112), we get a palindrome (323342243323).

The spelling of 211220221211 in words is "two hundred eleven billion, two hundred twenty million, two hundred twenty-one thousand, two hundred eleven".