21310323 has 4 divisors (see below), whose sum is σ = 28413768. Its totient is φ = 14206880.

The previous prime is 21310321. The next prime is 21310337. The reversal of 21310323 is 32301312.

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 21310323 - 2¹ = 21310321 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21310321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3551718 + ... + 3551723.

It is an arithmetic number, because the mean of its divisors is an integer number (7103442).

Almost surely, 2^21310323 is an apocalyptic number.

21310323 is a deficient number, since it is larger than the sum of its proper divisors (7103445).

21310323 is an equidigital number, since it uses as much as digits as its factorization.

21310323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7103444.

The product of its (nonzero) digits is 108, while the sum is 15.

The square root of 21310323 is about 4616.3105398142. The cubic root of 21310323 is about 277.2447584046.

Adding to 21310323 its reverse (32301312), we get a palindrome (53611635).

The spelling of 21310323 in words is "twenty-one million, three hundred ten thousand, three hundred twenty-three".