665866704 has 80 divisors (see below), whose sum is σ = 1815598080. Its totient is φ = 209704320.

The previous prime is 665866681. The next prime is 665866711. The reversal of 665866704 is 407668566.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447049 + ... + 448535.

It is an arithmetic number, because the mean of its divisors is an integer number (22694976).

Almost surely, 2^665866704 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665866704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907799040).

665866704 is an abundant number, since it is smaller than the sum of its proper divisors (1149731376).

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

665866704 is a wasteful number, since it uses less digits than its factorization.

665866704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2008 (or 2002 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 48.

The square root of 665866704 is about 25804.3931143517. The cubic root of 665866704 is about 873.2309090042.

The spelling of 665866704 in words is "six hundred sixty-five million, eight hundred sixty-six thousand, seven hundred four".