231212013121 has 4 divisors (see below), whose sum is σ = 231497813700. Its totient is φ = 230926212544.

The previous prime is 231212013119. The next prime is 231212013127. The reversal of 231212013121 is 121310212132.

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

It can be written as a sum of positive squares in 2 ways, for example, as 116629763121 + 114582250000 = 341511^2 + 338500^2 .

It is a cyclic number.

It is not a de Polignac number, because 231212013121 - 2¹ = 231212013119 is a prime.

It is a super-2 number, since 2×231212013121² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (231212013127) 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, 142899076 + ... + 142900693.

It is an arithmetic number, because the mean of its divisors is an integer number (57874453425).

Almost surely, 2^231212013121 is an apocalyptic number.

It is an amenable number.

231212013121 is a deficient number, since it is larger than the sum of its proper divisors (285800579).

231212013121 is an equidigital number, since it uses as much as digits as its factorization.

231212013121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285800578.

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

Adding to 231212013121 its reverse (121310212132), we get a palindrome (352522225253).

The spelling of 231212013121 in words is "two hundred thirty-one billion, two hundred twelve million, thirteen thousand, one hundred twenty-one".