211142221 has 4 divisors (see below), whose sum is σ = 211191100. Its totient is φ = 211093344.

The previous prime is 211142161. The next prime is 211142249. The reversal of 211142221 is 122241112.

211142221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 48860100 + 162282121 = 6990^2 + 12739^2 .

It is a cyclic number.

It is not a de Polignac number, because 211142221 - 2¹⁵ = 211109453 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211142195 and 211142204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211142821) 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, 17256 + ... + 26833.

It is an arithmetic number, because the mean of its divisors is an integer number (52797775).

Almost surely, 2^211142221 is an apocalyptic number.

It is an amenable number.

211142221 is a deficient number, since it is larger than the sum of its proper divisors (48879).

211142221 is an equidigital number, since it uses as much as digits as its factorization.

211142221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48878.

The product of its digits is 64, while the sum is 16.

The square root of 211142221 is about 14530.7336703967. The cubic root of 211142221 is about 595.4679096022.

Adding to 211142221 its reverse (122241112), we get a palindrome (333383333).

The spelling of 211142221 in words is "two hundred eleven million, one hundred forty-two thousand, two hundred twenty-one".