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12731 = 29439
BaseRepresentation
bin11000110111011
3122110112
43012323
5401411
6134535
752055
oct30673
918415
1012731
119624
12744b
135a44
1448d5
153b8b
hex31bb

12731 has 4 divisors (see below), whose sum is σ = 13200. Its totient is φ = 12264.

The previous prime is 12721. The next prime is 12739. The reversal of 12731 is 13721.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-12731 is a prime.

It is a super-2 number, since 2×127312 = 324156722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12739) 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, 191 + ... + 248.

It is an arithmetic number, because the mean of its divisors is an integer number (3300).

212731 is an apocalyptic number.

12731 is a deficient number, since it is larger than the sum of its proper divisors (469).

12731 is an equidigital number, since it uses as much as digits as its factorization.

12731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468.

The product of its digits is 42, while the sum is 14.

The square root of 12731 is about 112.8317331250. The cubic root of 12731 is about 23.3500333961.

Subtracting 12731 from its reverse (13721), we obtain a triangular number (990 = T44).

The spelling of 12731 in words is "twelve thousand, seven hundred thirty-one".

Divisors: 1 29 439 12731