| Base | Representation |
|---|---|
| bin | 1001010100100… |
| … | …10001100100000 |
| 3 | 12110010122020100 |
| 4 | 10222102030200 |
| 5 | 130004142230 |
| 6 | 11431542400 |
| 7 | 1636430133 |
| oct | 452221440 |
| 9 | 173118210 |
| 10 | 78193440 |
| 11 | 40157986 |
| 12 | 2222aa00 |
| 13 | 1327a010 |
| 14 | a55621a |
| 15 | 6ce8660 |
| hex | 4a92320 |
78193440 has 144 divisors (see below), whose sum is σ = 287429688. Its totient is φ = 19243008.
The previous prime is 78193433. The next prime is 78193447. The reversal of 78193440 is 4439187.
It is a happy number.
It is an interprime number because it is at equal distance from previous prime (78193433) and next prime (78193447).
It can be written as a sum of positive squares in 4 ways, for example, as 65999376 + 12194064 = 8124^2 + 3492^2 .
It is a tau number, because it is divible by the number of its divisors (144).
It is a super-2 number, since 2×781934402 = 12228428118067200, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (36).
It is a zygodrome in base 12.
It is a junction number, because it is equal to n+sod(n) for n = 78193395 and 78193404.
It is not an unprimeable number, because it can be changed into a prime (78193447) by changing a digit.
It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16632 + ... + 20808.
Almost surely, 278193440 is an apocalyptic number.
It is an amenable number.
It is a practical number, because each smaller number is the sum of distinct divisors of 78193440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (143714844).
78193440 is an abundant number, since it is smaller than the sum of its proper divisors (209236248).
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
78193440 is a wasteful number, since it uses less digits than its factorization.
78193440 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 4211 (or 4200 counting only the distinct ones).
The product of its (nonzero) digits is 24192, while the sum is 36.
The square root of 78193440 is about 8842.7054683507. The cubic root of 78193440 is about 427.6187830384.
The spelling of 78193440 in words is "seventy-eight million, one hundred ninety-three thousand, four hundred forty".
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