665784487566 has 48 divisors (see below), whose sum is σ = 1573836000048. Its totient is φ = 201731904000.

The previous prime is 665784487549. The next prime is 665784487609.

665784487566 is a `hidden beast` number, since 6 + 6 + 5 + 7 + 84 + 487 + 5 + 66 = 666.

665784487566 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 665784487494 and 665784487503.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1790590 + ... + 2130206.

It is an arithmetic number, because the mean of its divisors is an integer number (32788250001).

Almost surely, 2^665784487566 is an apocalyptic number.

665784487566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665784487566 is an abundant number, since it is smaller than the sum of its proper divisors (908051512482).

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

665784487566 is a wasteful number, since it uses less digits than its factorization.

665784487566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349537 (or 349534 counting only the distinct ones).

The product of its digits is 1625702400, while the sum is 72.

The spelling of 665784487566 in words is "six hundred sixty-five billion, seven hundred eighty-four million, four hundred eighty-seven thousand, five hundred sixty-six".