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131281 = 532477
BaseRepresentation
bin100000000011010001
320200002021
4200003101
513200111
62451441
71054513
oct400321
9220067
10131281
118a6a7
1263b81
13479a7
1435bb3
1528d71
hex200d1

131281 has 4 divisors (see below), whose sum is σ = 133812. Its totient is φ = 128752.

The previous prime is 131267. The next prime is 131293. The reversal of 131281 is 182131.

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

It can be written as a sum of positive squares in 2 ways, for example, as 80656 + 50625 = 284^2 + 225^2 .

It is a cyclic number.

It is not a de Polignac number, because 131281 - 25 = 131249 is a prime.

It is a super-2 number, since 2×1312812 = 34469401922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (131221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1186 + ... + 1291.

It is an arithmetic number, because the mean of its divisors is an integer number (33453).

2131281 is an apocalyptic number.

It is an amenable number.

131281 is a deficient number, since it is larger than the sum of its proper divisors (2531).

131281 is an equidigital number, since it uses as much as digits as its factorization.

131281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2530.

The product of its digits is 48, while the sum is 16.

The square root of 131281 is about 362.3272001934. The cubic root of 131281 is about 50.8238185781.

It can be divided in two parts, 13 and 1281, that multiplied together give a triangular number (16653 = T182).

The spelling of 131281 in words is "one hundred thirty-one thousand, two hundred eighty-one".

Divisors: 1 53 2477 131281