212431121021 has 4 divisors (see below), whose sum is σ = 242778424032. Its totient is φ = 182083818012.

The previous prime is 212431121009. The next prime is 212431121053. The reversal of 212431121021 is 120121134212.

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 212431121021 - 2¹⁴ = 212431104637 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 212431120984 and 212431121002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212431127021) 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, 15173651495 + ... + 15173651508.

It is an arithmetic number, because the mean of its divisors is an integer number (60694606008).

Almost surely, 2^212431121021 is an apocalyptic number.

It is an amenable number.

212431121021 is a deficient number, since it is larger than the sum of its proper divisors (30347303011).

212431121021 is an equidigital number, since it uses as much as digits as its factorization.

212431121021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30347303010.

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 212431121021 its reverse (120121134212), we get a palindrome (332552255233).

The spelling of 212431121021 in words is "two hundred twelve billion, four hundred thirty-one million, one hundred twenty-one thousand, twenty-one".