27577 is a member of OEIS A046034: numbers whose digits are primes. The remaining 27**** numbers are:

27722, 27723, 27725, 27727, 27732, 27733, 27735, 27737, 27752, 27753, 27755, 27757, 27772, 27773, 27775, 27777

27577 is a happy and sphenic number.

27577 is a number containing the digit 7 three times and the remaining two digits (2 and 5) add to 7. There are only 12 such numbers in the range up to 40000. They are 16777, 17677, 17767, 17776, 25777, 27577, 27757, 27775, 34777, 37477, 37747, 37774.

27577 can be rendered as a digit equation as follows:

(-2 + 7) / 5 = 7 / 7