665639360 has 56 divisors (see below), whose sum is σ = 1593250560. Its totient is φ = 264879104.

The previous prime is 665639341. The next prime is 665639363. The reversal of 665639360 is 63936566.

665639360 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (44) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665639363) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57761 + ... + 68319.

Almost surely, 2^665639360 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 665639360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (796625280).

665639360 is an abundant number, since it is smaller than the sum of its proper divisors (927611200).

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

665639360 is a wasteful number, since it uses less digits than its factorization.

665639360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10773 (or 10763 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 44.

The square root of 665639360 is about 25799.9875968962. The cubic root of 665639360 is about 873.1315165359.

The spelling of 665639360 in words is "six hundred sixty-five million, six hundred thirty-nine thousand, three hundred sixty".