21727027 has 4 divisors (see below), whose sum is σ = 24830896. Its totient is φ = 18623160.

The previous prime is 21727009. The next prime is 21727081. The reversal of 21727027 is 72072712.

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 21727027 - 2²³ = 13338419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21726986 and 21727004.

It is not an unprimeable number, because it can be changed into a prime (21727087) 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, 1551924 + ... + 1551937.

It is an arithmetic number, because the mean of its divisors is an integer number (6207724).

Almost surely, 2^21727027 is an apocalyptic number.

21727027 is a deficient number, since it is larger than the sum of its proper divisors (3103869).

21727027 is an equidigital number, since it uses as much as digits as its factorization.

21727027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3103868.

The product of its (nonzero) digits is 2744, while the sum is 28.

The square root of 21727027 is about 4661.2259117104. The cubic root of 21727027 is about 279.0401958162.

Adding to 21727027 its reverse (72072712), we get a palindrome (93799739).

The spelling of 21727027 in words is "twenty-one million, seven hundred twenty-seven thousand, twenty-seven".