665601565 has 8 divisors (see below), whose sum is σ = 798872760. Its totient is φ = 532380672.

The previous prime is 665601551. The next prime is 665601569. The reversal of 665601565 is 565106566.

665601565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 79816356 + 585785209 = 8934^2 + 24203^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 665601565 - 2¹³ = 665593373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665601569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29101 + ... + 46669.

It is an arithmetic number, because the mean of its divisors is an integer number (99859095).

Almost surely, 2^665601565 is an apocalyptic number.

It is an amenable number.

665601565 is a deficient number, since it is larger than the sum of its proper divisors (133271195).

665601565 is a wasteful number, since it uses less digits than its factorization.

665601565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25151.

The product of its (nonzero) digits is 162000, while the sum is 40.

The square root of 665601565 is about 25799.2551249062. The cubic root of 665601565 is about 873.1149907552.

The spelling of 665601565 in words is "six hundred sixty-five million, six hundred one thousand, five hundred sixty-five".