| Base | Representation |
|---|---|
| bin | 100011110100… |
| … | …0111101101100 |
| 3 | 1022100010100000 |
| 4 | 1013220331230 |
| 5 | 14301430022 |
| 6 | 1510304300 |
| 7 | 315425136 |
| oct | 107507554 |
| 9 | 38303300 |
| 10 | 18780012 |
| 11 | a667779 |
| 12 | 6358090 |
| 13 | 3b77044 |
| 14 | 26cc056 |
| 15 | 19ae6ac |
| hex | 11e8f6c |
18780012 has 54 divisors (see below), whose sum is σ = 49586628. Its totient is φ = 6214968.
The previous prime is 18780011. The next prime is 18780043. The reversal of 18780012 is 21008781.
It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.
It is a tau number, because it is divible by the number of its divisors (54).
It is a Harshad number since it is a multiple of its sum of digits (27).
It is not an unprimeable number, because it can be changed into a prime (18780011) by changing a digit.
It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 135039 + ... + 135177.
Almost surely, 218780012 is an apocalyptic number.
18780012 is a gapful number since it is divisible by the number (12) 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 18780012, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24793314).
18780012 is an abundant number, since it is smaller than the sum of its proper divisors (30806616).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
18780012 is an equidigital number, since it uses as much as digits as its factorization.
18780012 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 297 (or 144 counting only the distinct ones).
The product of its (nonzero) digits is 896, while the sum is 27.
The square root of 18780012 is about 4333.5911205373. The cubic root of 18780012 is about 265.8063112199.
Multiplying 18780012 by its sum of digits (27), we get a square (507060324 = 225182).
18780012 divided by its sum of digits (27) gives a square (695556 = 8342).
Adding to 18780012 its reverse (21008781), we get a palindrome (39788793).
The spelling of 18780012 in words is "eighteen million, seven hundred eighty thousand, twelve".
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