211211210111221 has 32 divisors (see below), whose sum is σ = 222096698081280. Its totient is φ = 200575483416000.

The previous prime is 211211210111137. The next prime is 211211210111233. The reversal of 211211210111221 is 122111012112112.

It is a cyclic number.

It is not a de Polignac number, because 211211210111221 - 2⁷ = 211211210111093 is a prime.

It is a super-2 number, since 2×211211210111221² (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 (211211210111281) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3423886840 + ... + 3423948526.

It is an arithmetic number, because the mean of its divisors is an integer number (6940521815040).

Almost surely, 2^{211211210111221} is an apocalyptic number.

It is an amenable number.

211211210111221 is a deficient number, since it is larger than the sum of its proper divisors (10885487970059).

211211210111221 is a wasteful number, since it uses less digits than its factorization.

211211210111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64465.

The product of its (nonzero) digits is 32, while the sum is 19.

Adding to 211211210111221 its reverse (122111012112112), we get a palindrome (333322222223333).

The spelling of 211211210111221 in words is "two hundred eleven trillion, two hundred eleven billion, two hundred ten million, one hundred eleven thousand, two hundred twenty-one".