2111121221 has 8 divisors (see below), whose sum is σ = 2308176000. Its totient is φ = 1914922240.

The previous prime is 2111121209. The next prime is 2111121239. The reversal of 2111121221 is 1221211112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-2111121221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2111121196 and 2111121205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111121241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 208781 + ... + 218658.

It is an arithmetic number, because the mean of its divisors is an integer number (288522000).

Almost surely, 2^2111121221 is an apocalyptic number.

It is an amenable number.

2111121221 is a deficient number, since it is larger than the sum of its proper divisors (197054779).

2111121221 is a wasteful number, since it uses less digits than its factorization.

2111121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 427899.

The product of its digits is 16, while the sum is 14.

The square root of 2111121221 is about 45946.9391907666. The cubic root of 2111121221 is about 1282.8357582075.

Adding to 2111121221 its reverse (1221211112), we get a palindrome (3332332333).

It can be divided in two parts, 211112 and 1221, that multiplied together give a palindrome (257767752).

The spelling of 2111121221 in words is "two billion, one hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".