66655 has 4 divisors (see below), whose sum is σ = 79992. Its totient is φ = 53320.

The previous prime is 66653. The next prime is 66683. The reversal of 66655 is 55666.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 66655 - 2¹ = 66653 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is a zygodrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6661 + ... + 6670.

It is an arithmetic number, because the mean of its divisors is an integer number (19998).

2⁶⁶⁶⁵⁵ is an apocalyptic number.

66655 is a deficient number, since it is larger than the sum of its proper divisors (13337).

66655 is a wasteful number, since it uses less digits than its factorization.

66655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13336.

The product of its digits is 5400, while the sum is 28.

The square root of 66655 is about 258.1762963558. The cubic root of 66655 is about 40.5456478651.

It can be divided in two parts, 6665 and 5, that added together give a triangular number (6670 = T₁₁₅).

The spelling of 66655 in words is "sixty-six thousand, six hundred fifty-five".