21226771 has 2 divisors, whose sum is σ = 21226772. Its totient is φ = 21226770.

The previous prime is 21226759. The next prime is 21226823. The reversal of 21226771 is 17762212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21226771 - 2¹⁷ = 21095699 is a prime.

It is not a weakly prime, because it can be changed into another prime (21226741) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613385 + 10613386.

It is an arithmetic number, because the mean of its divisors is an integer number (10613386).

Almost surely, 2^21226771 is an apocalyptic number.

21226771 is a deficient number, since it is larger than the sum of its proper divisors (1).

21226771 is an equidigital number, since it uses as much as digits as its factorization.

21226771 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2352, while the sum is 28.

The square root of 21226771 is about 4607.2520009220. The cubic root of 21226771 is about 276.8819499841.

Adding to 21226771 its reverse (17762212), we get a palindrome (38988983).

It can be divided in two parts, 2 and 1226771, that multiplied together give a palindrome (2453542).

The spelling of 21226771 in words is "twenty-one million, two hundred twenty-six thousand, seven hundred seventy-one".