665356653566 has 16 divisors (see below), whose sum is σ = 1089041701248. Its totient is φ = 302358101400.

The previous prime is 665356653523. The next prime is 665356653569.

665356653566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×665356653566² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 665356653499 and 665356653508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665356653569) 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, 3748340 + ... + 3921831.

It is an arithmetic number, because the mean of its divisors is an integer number (68065106328).

Almost surely, 2^665356653566 is an apocalyptic number.

665356653566 is a deficient number, since it is larger than the sum of its proper divisors (423685047682).

665356653566 is a wasteful number, since it uses less digits than its factorization.

665356653566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7674127.

The product of its digits is 262440000, while the sum is 62.

The spelling of 665356653566 in words is "six hundred sixty-five billion, three hundred fifty-six million, six hundred fifty-three thousand, five hundred sixty-six".