21271253 has 2 divisors, whose sum is σ = 21271254. Its totient is φ = 21271252.

The previous prime is 21271247. The next prime is 21271259. The reversal of 21271253 is 35217212.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (21271247) and next prime (21271259).

It can be written as a sum of positive squares in only one way, i.e., 15856324 + 5414929 = 3982^2 + 2327^2 .

It is a cyclic number.

It is not a de Polignac number, because 21271253 - 2²² = 17076949 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 (21271259) 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, 10635626 + 10635627.

It is an arithmetic number, because the mean of its divisors is an integer number (10635627).

Almost surely, 2^21271253 is an apocalyptic number.

It is an amenable number.

21271253 is a deficient number, since it is larger than the sum of its proper divisors (1).

21271253 is an equidigital number, since it uses as much as digits as its factorization.

21271253 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 840, while the sum is 23.

The square root of 21271253 is about 4612.0768640603. The cubic root of 21271253 is about 277.0752227423.

Adding to 21271253 its reverse (35217212), we get a palindrome (56488465).

The spelling of 21271253 in words is "twenty-one million, two hundred seventy-one thousand, two hundred fifty-three".