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18768820 = 2257791697
BaseRepresentation
bin100011110011…
…0001110110100
31022022112222111
41013212032310
514301100240
61510140404
7315350410
oct107461664
938275874
1018768820
11a65a324
126351704
133b71c15
1426c7d40
1519ab1ea
hex11e63b4

18768820 has 48 divisors (see below), whose sum is σ = 45642240. Its totient is φ = 6349824.

The previous prime is 18768817. The next prime is 18768859. The reversal of 18768820 is 2886781.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10212 + ... + 11908.

It is an arithmetic number, because the mean of its divisors is an integer number (950880).

Almost surely, 218768820 is an apocalyptic number.

18768820 is a gapful number since it is divisible by the number (10) 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 18768820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22821120).

18768820 is an abundant number, since it is smaller than the sum of its proper divisors (26873420).

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

18768820 is a wasteful number, since it uses less digits than its factorization.

18768820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1792 (or 1790 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 40.

The square root of 18768820 is about 4332.2996202941. The cubic root of 18768820 is about 265.7534980588.

The spelling of 18768820 in words is "eighteen million, seven hundred sixty-eight thousand, eight hundred twenty".

Divisors: 1 2 4 5 7 10 14 20 28 35 70 79 140 158 316 395 553 790 1106 1580 1697 2212 2765 3394 5530 6788 8485 11060 11879 16970 23758 33940 47516 59395 118790 134063 237580 268126 536252 670315 938441 1340630 1876882 2681260 3753764 4692205 9384410 18768820