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31680 = 2632511
BaseRepresentation
bin111101111000000
31121110100
413233000
52003210
6402400
7161235
oct75700
947410
1031680
1121890
1216400
131155c
14b78c
1595c0
hex7bc0

31680 has 84 divisors (see below), whose sum is σ = 118872. Its totient is φ = 7680.

The previous prime is 31667. The next prime is 31687. The reversal of 31680 is 8613.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31687) by changing a digit.

31680 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2875 + ... + 2885.

231680 is an apocalyptic number.

31680 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (59436).

31680 is an abundant number, since it is smaller than the sum of its proper divisors (87192).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31680 is a wasteful number, since it uses less digits than its factorization.

31680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34 (or 21 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 18.

The square root of 31680 is about 177.9887636903. The cubic root of 31680 is about 31.6418395739.

The spelling of 31680 in words is "thirty-one thousand, six hundred eighty".

Divisors: 1 2 3 4 5 6 8 9 10 11 12 15 16 18 20 22 24 30 32 33 36 40 44 45 48 55 60 64 66 72 80 88 90 96 99 110 120 132 144 160 165 176 180 192 198 220 240 264 288 320 330 352 360 396 440 480 495 528 576 660 704 720 792 880 960 990 1056 1320 1440 1584 1760 1980 2112 2640 2880 3168 3520 3960 5280 6336 7920 10560 15840 31680