231320221021 has 4 divisors (see below), whose sum is σ = 231361103200. Its totient is φ = 231279338844.

The previous prime is 231320221019. The next prime is 231320221039. The reversal of 231320221021 is 120122023132.

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 a cyclic number.

It is not a de Polignac number, because 231320221021 - 2¹ = 231320221019 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 231320221021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231320221061) 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, 20432601 + ... + 20443918.

It is an arithmetic number, because the mean of its divisors is an integer number (57840275800).

Almost surely, 2^231320221021 is an apocalyptic number.

It is an amenable number.

231320221021 is a deficient number, since it is larger than the sum of its proper divisors (40882179).

231320221021 is an equidigital number, since it uses as much as digits as its factorization.

231320221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40882178.

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 231320221021 its reverse (120122023132), we get a palindrome (351442244153).

The spelling of 231320221021 in words is "two hundred thirty-one billion, three hundred twenty million, two hundred twenty-one thousand, twenty-one".