It is a sphenic number, since it is the product of 3 distinct primes.
It is a Duffinian number.
It is a plaindrome in base 3 and base 9.
It is a zygodrome in base 3.
It is a congruent number.
Being equal to 14×314-1, it is a generalized Woodall number.
Almost surely, 266961565 is an apocalyptic number.
It is an amenable number.
66961565 is a wasteful number, since it uses less digits than its factorization.
66961565 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1217499.
The square root of 66961565 is about 8183.0046437724. The cubic root of 66961565 is about 406.0771307107.
The spelling of 66961565 in words is "sixty-six million, nine hundred sixty-one thousand, five hundred sixty-five".