231212131021 has 4 divisors (see below), whose sum is σ = 236131538112. Its totient is φ = 226292723932.

The previous prime is 231212131001. The next prime is 231212131039. The reversal of 231212131021 is 120131212132.

231212131021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 231212131021 - 2⁷ = 231212130893 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 231212131021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231212131001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2459703475 + ... + 2459703568.

It is an arithmetic number, because the mean of its divisors is an integer number (59032884528).

Almost surely, 2^231212131021 is an apocalyptic number.

It is an amenable number.

231212131021 is a deficient number, since it is larger than the sum of its proper divisors (4919407091).

231212131021 is an equidigital number, since it uses as much as digits as its factorization.

231212131021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4919407090.

The product of its (nonzero) digits is 144, while the sum is 19.

Adding to 231212131021 its reverse (120131212132), we get a palindrome (351343343153).

The spelling of 231212131021 in words is "two hundred thirty-one billion, two hundred twelve million, one hundred thirty-one thousand, twenty-one".