2111221111 has 4 divisors (see below), whose sum is σ = 2113208272. Its totient is φ = 2109233952.

The previous prime is 2111221103. The next prime is 2111221127. The reversal of 2111221111 is 1111221112.

It is a happy number.

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 2111221111 - 2³ = 2111221103 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2111221091 and 2111221100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111225111) 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, 991986 + ... + 994111.

It is an arithmetic number, because the mean of its divisors is an integer number (528302068).

Almost surely, 2^2111221111 is an apocalyptic number.

2111221111 is a deficient number, since it is larger than the sum of its proper divisors (1987161).

2111221111 is a wasteful number, since it uses less digits than its factorization.

2111221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1987160.

The product of its digits is 8, while the sum is 13.

The square root of 2111221111 is about 45948.0261926451. The cubic root of 2111221111 is about 1282.8559908121.

Adding to 2111221111 its reverse (1111221112), we get a palindrome (3222442223).

Subtracting from 2111221111 its reverse (1111221112), we obtain a palindrome (999999999).

The spelling of 2111221111 in words is "two billion, one hundred eleven million, two hundred twenty-one thousand, one hundred eleven".