665563661569 has 8 divisors (see below), whose sum is σ = 696871530432. Its totient is φ = 634453319280.

The previous prime is 665563661561. The next prime is 665563661597. The reversal of 665563661569 is 965166365566.

665563661569 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 665563661569 - 2³ = 665563661561 is a prime.

It is a super-2 number, since 2×665563661569² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 665563661569.

It is not an unprimeable number, because it can be changed into a prime (665563661561) 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, 49374747 + ... + 49388224.

It is an arithmetic number, because the mean of its divisors is an integer number (87108941304).

Almost surely, 2^665563661569 is an apocalyptic number.

It is an amenable number.

665563661569 is a deficient number, since it is larger than the sum of its proper divisors (31307868863).

665563661569 is a wasteful number, since it uses less digits than its factorization.

665563661569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 98763287.

The product of its digits is 157464000, while the sum is 64.

The spelling of 665563661569 in words is "six hundred sixty-five billion, five hundred sixty-three million, six hundred sixty-one thousand, five hundred sixty-nine".