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68378081 is a prime number
BaseRepresentation
bin1000001001101…
…01110111100001
311202122222002112
410010311313201
5120001044311
610441325105
71460130002
oct404656741
9152588075
1068378081
1135663512
121aa96795
1311221505
14911d1a9
15600a28b
hex4135de1

68378081 has 2 divisors, whose sum is σ = 68378082. Its totient is φ = 68378080.

The previous prime is 68378069. The next prime is 68378083. The reversal of 68378081 is 18087386.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61701025 + 6677056 = 7855^2 + 2584^2 .

It is a cyclic number.

It is not a de Polignac number, because 68378081 - 214 = 68361697 is a prime.

It is a super-2 number, since 2×683780812 = 9351123922485122, which contains 22 as substring.

It is a Sophie Germain prime.

Together with 68378083, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (68378083) by changing a digit.

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 as a sum of consecutive naturals, namely, 34189040 + 34189041.

It is an arithmetic number, because the mean of its divisors is an integer number (34189041).

Almost surely, 268378081 is an apocalyptic number.

It is an amenable number.

68378081 is a deficient number, since it is larger than the sum of its proper divisors (1).

68378081 is an equidigital number, since it uses as much as digits as its factorization.

68378081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64512, while the sum is 41.

The square root of 68378081 is about 8269.1040022484. The cubic root of 68378081 is about 408.9205812603.

The spelling of 68378081 in words is "sixty-eight million, three hundred seventy-eight thousand, eighty-one".