66605 has 16 divisors (see below), whose sum is σ = 100224. Its totient is φ = 41280.

The previous prime is 66601. The next prime is 66617. The reversal of 66605 is 50666.

66605 = T₃₄ + T₃₅ + ... + T₇₅.

66605 = 148² + 149² + 150².

It is a happy number.

It is not a de Polignac number, because 66605 - 2² = 66601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66601) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 299 + ... + 471.

It is an arithmetic number, because the mean of its divisors is an integer number (6264).

2⁶⁶⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

66605 is a deficient number, since it is larger than the sum of its proper divisors (33619).

66605 is a wasteful number, since it uses less digits than its factorization.

66605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 66605 is about 258.0794451327. The cubic root of 66605 is about 40.5355071429.

The spelling of 66605 in words is "sixty-six thousand, six hundred five".