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7980 = 2235719
BaseRepresentation
bin1111100101100
3101221120
41330230
5223410
6100540
732160
oct17454
911846
107980
115aa5
124750
13382b
142ca0
152570
hex1f2c

7980 has 48 divisors (see below), whose sum is σ = 26880. Its totient is φ = 1728.

The previous prime is 7963. The next prime is 7993. The reversal of 7980 is 897.

7980 = 282 + 292 + ... + 352.

7980 is nontrivially palindromic in base 11.

It is a self number, because there is not a number n which added to its sum of digits gives 7980.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 411 + ... + 429.

It is an arithmetic number, because the mean of its divisors is an integer number (560).

7980 is a gapful number since it is divisible by the number (70) 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 7980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13440).

7980 is an abundant number, since it is smaller than the sum of its proper divisors (18900).

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

7980 is a wasteful number, since it uses less digits than its factorization.

7980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38 (or 36 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 7980 is about 89.3308457365. The cubic root of 7980 is about 19.9833194251.

The spelling of 7980 in words is "seven thousand, nine hundred eighty".

Divisors: 1 2 3 4 5 6 7 10 12 14 15 19 20 21 28 30 35 38 42 57 60 70 76 84 95 105 114 133 140 190 210 228 266 285 380 399 420 532 570 665 798 1140 1330 1596 1995 2660 3990 7980