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18801980 = 2252713469
BaseRepresentation
bin100011110111…
…0010100111100
31022101020110122
41013232110330
514303130410
61510554112
7315546161
oct107562474
938336418
1018801980
11a68222a
126368938
133b84042
1426d6068
1519b5e55
hex11ee53c

18801980 has 24 divisors (see below), whose sum is σ = 39641280. Its totient is φ = 7490880.

The previous prime is 18801977. The next prime is 18801989. The reversal of 18801980 is 8910881.

18801980 is a modest number, since divided by 1980 gives 1880 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 18801980.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18801989) 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, 3686 + ... + 7154.

It is an arithmetic number, because the mean of its divisors is an integer number (1651720).

Almost surely, 218801980 is an apocalyptic number.

18801980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18801980 is an abundant number, since it is smaller than the sum of its proper divisors (20839300).

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

18801980 is a wasteful number, since it uses less digits than its factorization.

18801980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3749 (or 3747 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 35.

The square root of 18801980 is about 4336.1249981983. The cubic root of 18801980 is about 265.9099135268.

The spelling of 18801980 in words is "eighteen million, eight hundred one thousand, nine hundred eighty".

Divisors: 1 2 4 5 10 20 271 542 1084 1355 2710 3469 5420 6938 13876 17345 34690 69380 940099 1880198 3760396 4700495 9400990 18801980