A divisor 
of a positive integer 
is biunitary if the greatest common unitary divisor of 
and 
is 1. For a prime power 
, the biunitary divisors are the powers 1, 
, 
, ..., 
, except for 
when 
is even (Cohen 1990).
Biunitary Divisor
See also
Divisor, k-ary Divisor, Unitary DivisorExplore with Wolfram|Alpha
References
Cohen, G. L. "On an Integer's Infinitary Divisors." Math. Comput. 54, 395-411, 1990.Suryanarayana, D. "The Number of Bi-Unitary Divisors of an Integer." The Theory of Arithmetic Functions (Proc. Conf., Western Michigan Univ., Kalamazoo, Mich., 1971. New York: Springer-Verlag, pp. 273-282, 1972.Suryanarayana, D. and Rao, R. S. R. C. "The Number of Bi-Unitary Divisors of an Integer. II." J. Indian Math. Soc. 39, 261-280, 1975.Referenced on Wolfram|Alpha
Biunitary DivisorCite this as:
Weisstein, Eric W. "Biunitary Divisor." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/BiunitaryDivisor.html