211221133 has 4 divisors (see below), whose sum is σ = 211479228. Its totient is φ = 210963040.

The previous prime is 211221091. The next prime is 211221169. The reversal of 211221133 is 331122112.

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 33212169 + 178008964 = 5763^2 + 13342^2 .

It is a cyclic number.

It is not a de Polignac number, because 211221133 - 2⁹ = 211220621 is a prime.

It is a super-2 number, since 2×211221133² = 89228734051607378, which 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 (211221533) 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, 127816 + ... + 129457.

It is an arithmetic number, because the mean of its divisors is an integer number (52869807).

Almost surely, 2^211221133 is an apocalyptic number.

It is an amenable number.

211221133 is a deficient number, since it is larger than the sum of its proper divisors (258095).

211221133 is an equidigital number, since it uses as much as digits as its factorization.

211221133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258094.

The product of its digits is 72, while the sum is 16.

The square root of 211221133 is about 14533.4487648321. The cubic root of 211221133 is about 595.5420834785.

Adding to 211221133 its reverse (331122112), we get a palindrome (542343245).

The spelling of 211221133 in words is "two hundred eleven million, two hundred twenty-one thousand, one hundred thirty-three".