21323421121 has 2 divisors, whose sum is σ = 21323421122. Its totient is φ = 21323421120.

The previous prime is 21323421043. The next prime is 21323421127. The reversal of 21323421121 is 12112432312.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19457181121 + 1866240000 = 139489^2 + 43200^2 .

It is a cyclic number.

It is not a de Polignac number, because 21323421121 - 2⁹ = 21323420609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21323421092 and 21323421101.

It is not a weakly prime, because it can be changed into another prime (21323421127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10661710560 + 10661710561.

It is an arithmetic number, because the mean of its divisors is an integer number (10661710561).

Almost surely, 2^21323421121 is an apocalyptic number.

It is an amenable number.

21323421121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21323421121 is an equidigital number, since it uses as much as digits as its factorization.

21323421121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 22.

Adding to 21323421121 its reverse (12112432312), we get a palindrome (33435853433).

The spelling of 21323421121 in words is "twenty-one billion, three hundred twenty-three million, four hundred twenty-one thousand, one hundred twenty-one".