211110121221 has 4 divisors (see below), whose sum is σ = 281480161632. Its totient is φ = 140740080812.

The previous prime is 211110121217. The next prime is 211110121279. The reversal of 211110121221 is 122121011112.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 211110121221 - 2² = 211110121217 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 211110121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211110121421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35185020201 + ... + 35185020206.

It is an arithmetic number, because the mean of its divisors is an integer number (70370040408).

Almost surely, 2^211110121221 is an apocalyptic number.

It is an amenable number.

211110121221 is a deficient number, since it is larger than the sum of its proper divisors (70370040411).

211110121221 is an equidigital number, since it uses as much as digits as its factorization.

211110121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70370040410.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 211110121221 its reverse (122121011112), we get a palindrome (333231132333).

The spelling of 211110121221 in words is "two hundred eleven billion, one hundred ten million, one hundred twenty-one thousand, two hundred twenty-one".