231132121221 has 4 divisors (see below), whose sum is σ = 308176161632. Its totient is φ = 154088080812.

The previous prime is 231132121211. The next prime is 231132121243. The reversal of 231132121221 is 122121231132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 231132121221 - 2⁷ = 231132121093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231132121211) 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, 38522020201 + ... + 38522020206.

It is an arithmetic number, because the mean of its divisors is an integer number (77044040408).

Almost surely, 2^231132121221 is an apocalyptic number.

It is an amenable number.

231132121221 is a deficient number, since it is larger than the sum of its proper divisors (77044040411).

231132121221 is an equidigital number, since it uses as much as digits as its factorization.

231132121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77044040410.

The product of its digits is 288, while the sum is 21.

Adding to 231132121221 its reverse (122121231132), we get a palindrome (353253352353).

The spelling of 231132121221 in words is "two hundred thirty-one billion, one hundred thirty-two million, one hundred twenty-one thousand, two hundred twenty-one".