21231201323 has 4 divisors (see below), whose sum is σ = 21233567520. Its totient is φ = 21228835128.

The previous prime is 21231201319. The next prime is 21231201371. The reversal of 21231201323 is 32310213212.

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

It is a cyclic number.

It is not a de Polignac number, because 21231201323 - 2² = 21231201319 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21231201295 and 21231201304.

It is not an unprimeable number, because it can be changed into a prime (21231209323) 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, 1169588 + ... + 1187601.

It is an arithmetic number, because the mean of its divisors is an integer number (5308391880).

Almost surely, 2^21231201323 is an apocalyptic number.

21231201323 is a deficient number, since it is larger than the sum of its proper divisors (2366197).

21231201323 is an equidigital number, since it uses as much as digits as its factorization.

21231201323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2366196.

The product of its (nonzero) digits is 432, while the sum is 20.

Adding to 21231201323 its reverse (32310213212), we get a palindrome (53541414535).

The spelling of 21231201323 in words is "twenty-one billion, two hundred thirty-one million, two hundred one thousand, three hundred twenty-three".