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128185980 = 223513164341
BaseRepresentation
bin1111010001111…
…11011001111100
322221012112002220
413220333121330
5230303422410
620415245340
73114364026
oct750773174
9287175086
10128185980
11663a302a
1236b19850
1320731bc0
141304b016
15b3c1070
hex7a3f67c

128185980 has 48 divisors (see below), whose sum is σ = 386532384. Its totient is φ = 31553280.

The previous prime is 128185963. The next prime is 128185987. The reversal of 128185980 is 89581821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128185987) 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, 81391 + ... + 82950.

It is an arithmetic number, because the mean of its divisors is an integer number (8052758).

Almost surely, 2128185980 is an apocalyptic number.

128185980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

128185980 is an abundant number, since it is smaller than the sum of its proper divisors (258346404).

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

128185980 is a wasteful number, since it uses less digits than its factorization.

128185980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164366 (or 164364 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 42.

The square root of 128185980 is about 11321.9247480276. The cubic root of 128185980 is about 504.2123852931.

The spelling of 128185980 in words is "one hundred twenty-eight million, one hundred eighty-five thousand, nine hundred eighty".

Divisors: 1 2 3 4 5 6 10 12 13 15 20 26 30 39 52 60 65 78 130 156 195 260 390 780 164341 328682 493023 657364 821705 986046 1643410 1972092 2136433 2465115 3286820 4272866 4930230 6409299 8545732 9860460 10682165 12818598 21364330 25637196 32046495 42728660 64092990 128185980