| Base | Representation |
|---|---|
| bin | 100101110111111101… |
| … | …1100100101100000000 |
| 3 | 21202221100202001200000 |
| 4 | 1023233323210230000 |
| 5 | 2313033201021340 |
| 6 | 101210434400000 |
| 7 | 5606360150262 |
| oct | 1135773445400 |
| 9 | 252840661600 |
| 10 | 81334782720 |
| 11 | 315484010a4 |
| 12 | 1391aa30000 |
| 13 | 789282a989 |
| 14 | 3d18151b32 |
| 15 | 21b077ed30 |
| hex | 12efee4b00 |
81334782720 has 864 divisors, whose sum is σ = 308558315520. Its totient is φ = 20483850240.
The previous prime is 81334782713. The next prime is 81334782721. The reversal of 81334782720 is 2728743318.
81334782720 is a `hidden beast` number, since 8 + 133 + 478 + 27 + 20 = 666.
It is a tau number, because it is divible by the number of its divisors (864).
It is a super-3 number, since 3×813347827203 (a number of 34 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.
It is a Harshad number since it is a multiple of its sum of digits (45).
It is not an unprimeable number, because it can be changed into a prime (81334782721) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (19) of ones.
It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 640431297 + ... + 640431423.
It is an arithmetic number, because the mean of its divisors is an integer number (357127680).
Almost surely, 281334782720 is an apocalyptic number.
81334782720 is a gapful number since it is divisible by the number (80) 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 81334782720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (154279157760).
81334782720 is an abundant number, since it is smaller than the sum of its proper divisors (227223532800).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
81334782720 is a wasteful number, since it uses less digits than its factorization.
81334782720 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 263 (or 237 counting only the distinct ones).
The product of its (nonzero) digits is 451584, while the sum is 45.
The spelling of 81334782720 in words is "eighty-one billion, three hundred thirty-four million, seven hundred eighty-two thousand, seven hundred twenty".
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