| Base | Representation |
|---|---|
| bin | 100101111010110110… |
| … | …0101010111000000000 |
| 3 | 21210012002210210121100 |
| 4 | 1023311230222320000 |
| 5 | 2313232433223300 |
| 6 | 101224212254400 |
| 7 | 5611643443164 |
| oct | 1136554527000 |
| 9 | 253162723540 |
| 10 | 81431539200 |
| 11 | 31597a87730 |
| 12 | 13947311400 |
| 13 | 78a98a702b |
| 14 | 3d26d3aca4 |
| 15 | 21b8ee3700 |
| hex | 12f5b2ae00 |
81431539200 has 720 divisors, whose sum is σ = 320580374400. Its totient is φ = 19576012800.
The previous prime is 81431539187. The next prime is 81431539213. The reversal of 81431539200 is 293513418.
81431539200 is a `hidden beast` number, since 81 + 43 + 1 + 539 + 2 + 0 + 0 = 666.
It is an interprime number because it is at equal distance from previous prime (81431539187) and next prime (81431539213).
It is a tau number, because it is divible by the number of its divisors (720).
It is a super-2 number, since 2×814315392002 (a number of 23 digits) contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (36).
It is a congruent number.
It is an unprimeable number.
It is a pernicious number, because its binary representation contains a prime number (17) of ones.
It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 226828621 + ... + 226828979.
It is an arithmetic number, because the mean of its divisors is an integer number (445250520).
Almost surely, 281431539200 is an apocalyptic number.
81431539200 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 81431539200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (160290187200).
81431539200 is an abundant number, since it is smaller than the sum of its proper divisors (239148835200).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
81431539200 is a wasteful number, since it uses less digits than its factorization.
81431539200 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 583 (or 559 counting only the distinct ones).
The product of its (nonzero) digits is 25920, while the sum is 36.
The spelling of 81431539200 in words is "eighty-one billion, four hundred thirty-one million, five hundred thirty-nine thousand, two hundred".
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