665707566 has 32 divisors (see below), whose sum is σ = 1342268928. Its totient is φ = 220101120.

The previous prime is 665707543. The next prime is 665707571.

665707566 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 540171 + ... + 541401.

It is an arithmetic number, because the mean of its divisors is an integer number (41945904).

Almost surely, 2^665707566 is an apocalyptic number.

665707566 is an abundant number, since it is smaller than the sum of its proper divisors (676561362).

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

665707566 is a wasteful number, since it uses less digits than its factorization.

665707566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896.

The product of its (nonzero) digits is 1587600, while the sum is 48.

The square root of 665707566 is about 25801.3093853781. The cubic root of 665707566 is about 873.1613378765.

The spelling of 665707566 in words is "six hundred sixty-five million, seven hundred seven thousand, five hundred sixty-six".