21727271 has 2 divisors, whose sum is σ = 21727272. Its totient is φ = 21727270.

The previous prime is 21727247. The next prime is 21727283. The reversal of 21727271 is 17272712.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21727271 - 2¹⁰ = 21726247 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21727231) 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, 10863635 + 10863636.

It is an arithmetic number, because the mean of its divisors is an integer number (10863636).

Almost surely, 2^21727271 is an apocalyptic number.

21727271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21727271 is an equidigital number, since it uses as much as digits as its factorization.

21727271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2744, while the sum is 29.

The square root of 21727271 is about 4661.2520850089. The cubic root of 21727271 is about 279.0412403763.

Adding to 21727271 its reverse (17272712), we get a palindrome (38999983).

The spelling of 21727271 in words is "twenty-one million, seven hundred twenty-seven thousand, two hundred seventy-one".