665650605 has 16 divisors (see below), whose sum is σ = 1082502144. Its totient is φ = 349193280.

The previous prime is 665650597. The next prime is 665650607. The reversal of 665650605 is 506056566.

It is a happy number.

It is not a de Polignac number, because 665650605 - 2³ = 665650597 is a prime.

It is a super-3 number, since 3×665650605³ (a number of 27 digits) contains 333 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665650607) 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, 362829 + ... + 364658.

It is an arithmetic number, because the mean of its divisors is an integer number (67656384).

Almost surely, 2^665650605 is an apocalyptic number.

It is an amenable number.

665650605 is a deficient number, since it is larger than the sum of its proper divisors (416851539).

665650605 is a wasteful number, since it uses less digits than its factorization.

665650605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727556.

The product of its (nonzero) digits is 162000, while the sum is 39.

The square root of 665650605 is about 25800.2055224372. The cubic root of 665650605 is about 873.1364332667.

The spelling of 665650605 in words is "six hundred sixty-five million, six hundred fifty thousand, six hundred five".