21727023 has 4 divisors (see below), whose sum is σ = 28969368. Its totient is φ = 14484680.

The previous prime is 21727009. The next prime is 21727081. The reversal of 21727023 is 32072712.

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 21727023 - 2¹⁴ = 21710639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21726984 and 21727002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21727093) 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, 3621168 + ... + 3621173.

It is an arithmetic number, because the mean of its divisors is an integer number (7242342).

Almost surely, 2^21727023 is an apocalyptic number.

21727023 is a deficient number, since it is larger than the sum of its proper divisors (7242345).

21727023 is an equidigital number, since it uses as much as digits as its factorization.

21727023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7242344.

The product of its (nonzero) digits is 1176, while the sum is 24.

The square root of 21727023 is about 4661.2254826387. The cubic root of 21727023 is about 279.0401786922.

Adding to 21727023 its reverse (32072712), we get a palindrome (53799735).

The spelling of 21727023 in words is "twenty-one million, seven hundred twenty-seven thousand, twenty-three".