211131321221 has 4 divisors (see below), whose sum is σ = 213221730444. Its totient is φ = 209040912000.

The previous prime is 211131321209. The next prime is 211131321227. The reversal of 211131321221 is 122123131112.

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 202761084100 + 8370237121 = 450290^2 + 91489^2 .

It is not a de Polignac number, because 211131321221 - 2²⁶ = 211064212357 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211131321193 and 211131321202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211131321227) 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, 1045204460 + ... + 1045204661.

It is an arithmetic number, because the mean of its divisors is an integer number (53305432611).

Almost surely, 2^211131321221 is an apocalyptic number.

It is an amenable number.

211131321221 is a deficient number, since it is larger than the sum of its proper divisors (2090409223).

211131321221 is a wasteful number, since it uses less digits than its factorization.

211131321221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2090409222.

The product of its digits is 144, while the sum is 20.

Adding to 211131321221 its reverse (122123131112), we get a palindrome (333254452333).

The spelling of 211131321221 in words is "two hundred eleven billion, one hundred thirty-one million, three hundred twenty-one thousand, two hundred twenty-one".