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21271 = 89239
BaseRepresentation
bin101001100010111
31002011211
411030113
51140041
6242251
7116005
oct51427
932154
1021271
1114a88
1210387
1398b3
147a75
156481
hex5317

21271 has 4 divisors (see below), whose sum is σ = 21600. Its totient is φ = 20944.

The previous prime is 21269. The next prime is 21277. The reversal of 21271 is 17212.

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 21271 - 21 = 21269 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 (21277) 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, 31 + ... + 208.

It is an arithmetic number, because the mean of its divisors is an integer number (5400).

221271 is an apocalyptic number.

21271 is a deficient number, since it is larger than the sum of its proper divisors (329).

21271 is an equidigital number, since it uses as much as digits as its factorization.

21271 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328.

The product of its digits is 28, while the sum is 13.

The square root of 21271 is about 145.8458089902. The cubic root of 21271 is about 27.7074124228.

Adding to 21271 its reverse (17212), we get a palindrome (38483).

It can be divided in two parts, 21 and 271, that added together give a palindrome (292).

The spelling of 21271 in words is "twenty-one thousand, two hundred seventy-one", and thus it is an iban number.

Divisors: 1 89 239 21271