665665650565 has 8 divisors (see below), whose sum is σ = 798807041568. Its totient is φ = 532527013200.

The previous prime is 665665650479. The next prime is 665665650577. The reversal of 665665650565 is 565056566566.

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

It is a de Polignac number, because none of the positive numbers 2^k-665665650565 is a prime.

It is a super-2 number, since 2×665665650565² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

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, 112827 + ... + 1159336.

It is an arithmetic number, because the mean of its divisors is an integer number (99850880196).

Almost surely, 2^665665650565 is an apocalyptic number.

It is an amenable number.

665665650565 is a deficient number, since it is larger than the sum of its proper divisors (133141391003).

665665650565 is a wasteful number, since it uses less digits than its factorization.

665665650565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376819.

The product of its (nonzero) digits is 145800000, while the sum is 61.

The spelling of 665665650565 in words is "six hundred sixty-five billion, six hundred sixty-five million, six hundred fifty thousand, five hundred sixty-five".