663605606665 has 8 divisors (see below), whose sum is σ = 802139332680. Its totient is φ = 527009415552.

The previous prime is 663605606647. The next prime is 663605606687. The reversal of 663605606665 is 566606506366.

663605606665 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 280421084304 + 383184522361 = 529548^2 + 619019^2 .

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 663605606665 - 2¹³ = 663605598473 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 484382970 + ... + 484384339.

It is an arithmetic number, because the mean of its divisors is an integer number (100267416585).

Almost surely, 2^663605606665 is an apocalyptic number.

It is an amenable number.

663605606665 is a deficient number, since it is larger than the sum of its proper divisors (138533726015).

663605606665 is a wasteful number, since it uses less digits than its factorization.

663605606665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 968767451.

The product of its (nonzero) digits is 20995200, while the sum is 55.

The spelling of 663605606665 in words is "six hundred sixty-three billion, six hundred five million, six hundred six thousand, six hundred sixty-five".