21230431121 has 4 divisors (see below), whose sum is σ = 21325635072. Its totient is φ = 21135227172.

The previous prime is 21230431097. The next prime is 21230431153. The reversal of 21230431121 is 12113403212.

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 21230431121 - 2²² = 21226236817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21230431093 and 21230431102.

It is not an unprimeable number, because it can be changed into a prime (21230431721) 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, 47601641 + ... + 47602086.

It is an arithmetic number, because the mean of its divisors is an integer number (5331408768).

Almost surely, 2^21230431121 is an apocalyptic number.

It is an amenable number.

21230431121 is a deficient number, since it is larger than the sum of its proper divisors (95203951).

21230431121 is an equidigital number, since it uses as much as digits as its factorization.

21230431121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95203950.

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21230431121 its reverse (12113403212), we get a palindrome (33343834333).

The spelling of 21230431121 in words is "twenty-one billion, two hundred thirty million, four hundred thirty-one thousand, one hundred twenty-one".