665793397566 has 24 divisors (see below), whose sum is σ = 1573693485624. Its totient is φ = 201755574960.

The previous prime is 665793397561. The next prime is 665793397567.

665793397566 is a `hidden beast` number, since 6 + 6 + 57 + 9 + 3 + 3 + 9 + 7 + 566 = 666.

665793397566 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 665793397494 and 665793397503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665793397561) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1681296261 + ... + 1681296656.

It is an arithmetic number, because the mean of its divisors is an integer number (65570561901).

Almost surely, 2^665793397566 is an apocalyptic number.

665793397566 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

665793397566 is an abundant number, since it is smaller than the sum of its proper divisors (907900088058).

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

665793397566 is a wasteful number, since it uses less digits than its factorization.

665793397566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3362592936 (or 3362592933 counting only the distinct ones).

The product of its digits is 1157360400, while the sum is 72.

The spelling of 665793397566 in words is "six hundred sixty-five billion, seven hundred ninety-three million, three hundred ninety-seven thousand, five hundred sixty-six".