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31887 = 331181
BaseRepresentation
bin111110010001111
31121202000
413302033
52010022
6403343
7161652
oct76217
947660
1031887
1121a59
1216553
131168b
14b899
1596ac
hex7c8f

31887 has 8 divisors (see below), whose sum is σ = 47280. Its totient is φ = 21240.

The previous prime is 31883. The next prime is 31891. The reversal of 31887 is 78813.

It is an interprime number because it is at equal distance from previous prime (31883) and next prime (31891).

It is not a de Polignac number, because 31887 - 22 = 31883 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 1181 = 31887 / (3 + 1 + 8 + 8 + 7).

31887 is a lucky number.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 31887.

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 31887.

It is not an unprimeable number, because it can be changed into a prime (31883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 564 + ... + 617.

It is an arithmetic number, because the mean of its divisors is an integer number (5910).

231887 is an apocalyptic number.

31887 is a deficient number, since it is larger than the sum of its proper divisors (15393).

31887 is a wasteful number, since it uses less digits than its factorization.

31887 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1190 (or 1184 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 31887 is about 178.5693142732. The cubic root of 31887 is about 31.7106068988.

The spelling of 31887 in words is "thirty-one thousand, eight hundred eighty-seven".

Divisors: 1 3 9 27 1181 3543 10629 31887