665694496566 has 96 divisors (see below), whose sum is σ = 1704761106048. Its totient is φ = 185444017920.

The previous prime is 665694496547. The next prime is 665694496567.

665694496566 is a `hidden beast` number, since 6 + 6 + 5 + 69 + 449 + 65 + 66 = 666.

665694496566 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 665694496494 and 665694496503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665694496567) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2154916 + ... + 2444391.

It is an arithmetic number, because the mean of its divisors is an integer number (17757928188).

Almost surely, 2^665694496566 is an apocalyptic number.

665694496566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665694496566 is an abundant number, since it is smaller than the sum of its proper divisors (1039066609482).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

665694496566 is a wasteful number, since it uses less digits than its factorization.

665694496566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4599386 (or 4599383 counting only the distinct ones).

The product of its digits is 1511654400, while the sum is 72.

The spelling of 665694496566 in words is "six hundred sixty-five billion, six hundred ninety-four million, four hundred ninety-six thousand, five hundred sixty-six".