231221330211 has 4 divisors (see below), whose sum is σ = 308295106952. Its totient is φ = 154147553472.

The previous prime is 231221330209. The next prime is 231221330233. The reversal of 231221330211 is 112033122132.

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

It is not a de Polignac number, because 231221330211 - 2¹ = 231221330209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231221330111) 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, 38536888366 + ... + 38536888371.

It is an arithmetic number, because the mean of its divisors is an integer number (77073776738).

Almost surely, 2^231221330211 is an apocalyptic number.

231221330211 is a deficient number, since it is larger than the sum of its proper divisors (77073776741).

231221330211 is an equidigital number, since it uses as much as digits as its factorization.

231221330211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77073776740.

The product of its (nonzero) digits is 432, while the sum is 21.

Adding to 231221330211 its reverse (112033122132), we get a palindrome (343254452343).

The spelling of 231221330211 in words is "two hundred thirty-one billion, two hundred twenty-one million, three hundred thirty thousand, two hundred eleven".