21672323 has 2 divisors, whose sum is σ = 21672324.
Its totient is φ = 21672322.
The previous prime is 21672319. The next prime is 21672337. The reversal of 21672323 is 32327612.
Adding to 21672323 its reverse (32327612), we get a palindrome (53999935).
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 21672323 - 22 = 21672319 is a prime.
It is an alternating number because its digits alternate between even and odd.
It is a junction number, because it is equal to n+sod(n) for n = 21672292 and 21672301.
It is not a weakly prime, because it can be changed into another prime (21672373) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (11) of ones.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10836161 + 10836162.
It is an arithmetic number, because the mean of its divisors is an integer number (10836162).
Almost surely, 221672323 is an apocalyptic number.
21672323 is a deficient number, since it is larger than the sum of its proper divisors (1).
21672323 is an equidigital number, since it uses as much as digits as its factorization.
21672323 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 3024, while the sum is 26.
The square root of 21672323 is about 4655.3542292719.
The cubic root of 21672323 is about 278.8058111819.
The spelling of 21672323 in words is "twenty-one million, six hundred seventy-two thousand, three hundred twenty-three".