21531314323 has 4 divisors (see below), whose sum is σ = 22467458448. Its totient is φ = 20595170200.

The previous prime is 21531314297. The next prime is 21531314327. The reversal of 21531314323 is 32341313512.

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 21531314323 - 2⁵ = 21531314291 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21531314291 and 21531314300.

It is not an unprimeable number, because it can be changed into a prime (21531314327) 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, 468072028 + ... + 468072073.

It is an arithmetic number, because the mean of its divisors is an integer number (5616864612).

Almost surely, 2^21531314323 is an apocalyptic number.

21531314323 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21531314323 is a deficient number, since it is larger than the sum of its proper divisors (936144125).

21531314323 is an equidigital number, since it uses as much as digits as its factorization.

21531314323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936144124.

The product of its digits is 6480, while the sum is 28.

Adding to 21531314323 its reverse (32341313512), we get a palindrome (53872627835).

The spelling of 21531314323 in words is "twenty-one billion, five hundred thirty-one million, three hundred fourteen thousand, three hundred twenty-three".