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68280761 = 2910921601
BaseRepresentation
bin1000001000111…
…10000110111001
311202111000121002
410010132012321
5114434441021
610435254345
71456243163
oct404360671
9152430532
1068280761
11355a738a
121aa4a3b5
13111b9123
1490d5933
155edb50b
hex411e1b9

68280761 has 8 divisors (see below), whose sum is σ = 71286600. Its totient is φ = 65318400.

The previous prime is 68280757. The next prime is 68280787. The reversal of 68280761 is 16708286.

It can be written as a sum of positive squares in 4 ways, for example, as 30691600 + 37589161 = 5540^2 + 6131^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 68280761 - 22 = 68280757 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68280731) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7640 + ... + 13961.

It is an arithmetic number, because the mean of its divisors is an integer number (8910825).

Almost surely, 268280761 is an apocalyptic number.

It is an amenable number.

68280761 is a deficient number, since it is larger than the sum of its proper divisors (3005839).

68280761 is a wasteful number, since it uses less digits than its factorization.

68280761 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21739.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 68280761 is about 8263.2173516131. The cubic root of 68280761 is about 408.7264886239.

The spelling of 68280761 in words is "sixty-eight million, two hundred eighty thousand, seven hundred sixty-one".

Divisors: 1 29 109 3161 21601 626429 2354509 68280761