231121021211 has 4 divisors (see below), whose sum is σ = 233905611912. Its totient is φ = 228336430512.

The previous prime is 231121021189. The next prime is 231121021231. The reversal of 231121021211 is 112120121132.

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 231121021211 - 2⁶ = 231121021147 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 231121021211.

It is not an unprimeable number, because it can be changed into a prime (231121021231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1392295226 + ... + 1392295391.

It is an arithmetic number, because the mean of its divisors is an integer number (58476402978).

Almost surely, 2^231121021211 is an apocalyptic number.

231121021211 is a deficient number, since it is larger than the sum of its proper divisors (2784590701).

231121021211 is an equidigital number, since it uses as much as digits as its factorization.

231121021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2784590700.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 231121021211 its reverse (112120121132), we get a palindrome (343241142343).

The spelling of 231121021211 in words is "two hundred thirty-one billion, one hundred twenty-one million, twenty-one thousand, two hundred eleven".