21271255 has 4 divisors (see below), whose sum is σ = 25525512. Its totient is φ = 17017000.

The previous prime is 21271253. The next prime is 21271259. The reversal of 21271255 is 55217212.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21271255 - 2¹ = 21271253 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21271253) 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, 2127121 + ... + 2127130.

It is an arithmetic number, because the mean of its divisors is an integer number (6381378).

Almost surely, 2^21271255 is an apocalyptic number.

21271255 is a deficient number, since it is larger than the sum of its proper divisors (4254257).

21271255 is an equidigital number, since it uses as much as digits as its factorization.

21271255 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4254256.

The product of its digits is 1400, while the sum is 25.

The square root of 21271255 is about 4612.0770808823. The cubic root of 21271255 is about 277.0752314262.

Adding to 21271255 its reverse (55217212), we get a palindrome (76488467).

The spelling of 21271255 in words is "twenty-one million, two hundred seventy-one thousand, two hundred fifty-five".