21323232121 has 8 divisors (see below), whose sum is σ = 21455880840. Its totient is φ = 21190691712.

The previous prime is 21323232043. The next prime is 21323232131. The reversal of 21323232121 is 12123232312.

It can be written as a sum of positive squares in 4 ways, for example, as 11950862400 + 9372369721 = 109320^2 + 96811^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21323232121 - 2²¹ = 21321134969 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21323232092 and 21323232101.

It is not an unprimeable number, because it can be changed into a prime (21323232131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 387501 + ... + 439093.

It is an arithmetic number, because the mean of its divisors is an integer number (2681985105).

Almost surely, 2^21323232121 is an apocalyptic number.

It is an amenable number.

21323232121 is a deficient number, since it is larger than the sum of its proper divisors (132648719).

21323232121 is a wasteful number, since it uses less digits than its factorization.

21323232121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54155.

The product of its digits is 864, while the sum is 22.

Adding to 21323232121 its reverse (12123232312), we get a palindrome (33446464433).

The spelling of 21323232121 in words is "twenty-one billion, three hundred twenty-three million, two hundred thirty-two thousand, one hundred twenty-one".