66501 has 10 divisors (see below), whose sum is σ = 99462. Its totient is φ = 44280.

The previous prime is 66499. The next prime is 66509. The reversal of 66501 is 10566.

66501 is a `hidden beast` number, since 665 + 0 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 50625 + 15876 = 225^2 + 126^2 .

It is not a de Polignac number, because 66501 - 2¹ = 66499 is a prime.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 66501.

It is not an unprimeable number, because it can be changed into a prime (66509) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 330 + ... + 491.

2⁶⁶⁵⁰¹ is an apocalyptic number.

It is an amenable number.

66501 is a deficient number, since it is larger than the sum of its proper divisors (32961).

66501 is an equidigital number, since it uses as much as digits as its factorization.

66501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 833 (or 824 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 66501 is about 257.8778780741. The cubic root of 66501 is about 40.5143981729.

The spelling of 66501 in words is "sixty-six thousand, five hundred one".