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28431 = 3713
BaseRepresentation
bin110111100001111
31110000000
412330033
51402211
6335343
7145614
oct67417
943000
1028431
111a3a7
1214553
13cc30
14a50b
158656
hex6f0f

28431 has 16 divisors (see below), whose sum is σ = 45920. Its totient is φ = 17496.

The previous prime is 28429. The next prime is 28433. The reversal of 28431 is 13482.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28429) and next prime (28433).

It is not a de Polignac number, because 28431 - 21 = 28429 is a prime.

It is a super-2 number, since 2×284312 = 1616643522, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

Its product of digits (192) is a multiple of the sum of its prime divisors (16).

It is a nialpdrome in base 3, base 9 and base 13.

It is a zygodrome in base 3.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28431.

It is not an unprimeable number, because it can be changed into a prime (28433) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2181 + ... + 2193.

It is an arithmetic number, because the mean of its divisors is an integer number (2870).

228431 is an apocalyptic number.

28431 is a deficient number, since it is larger than the sum of its proper divisors (17489).

28431 is an frugal number, since it uses more digits than its factorization.

28431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34 (or 16 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 28431 is about 168.6149459568. The cubic root of 28431 is about 30.5209029871.

The spelling of 28431 in words is "twenty-eight thousand, four hundred thirty-one".

Divisors: 1 3 9 13 27 39 81 117 243 351 729 1053 2187 3159 9477 28431