665505144 has 96 divisors (see below), whose sum is σ = 1828444800. Its totient is φ = 218661120.

The previous prime is 665505143. The next prime is 665505151. The reversal of 665505144 is 441505566.

665505144 is a `hidden beast` number, since 6 + 6 + 5 + 505 + 144 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 665505099 and 665505108.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665505143) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 2906022 + ... + 2906250.

It is an arithmetic number, because the mean of its divisors is an integer number (19046300).

Almost surely, 2^665505144 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 665505144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (914222400).

665505144 is an abundant number, since it is smaller than the sum of its proper divisors (1162939656).

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

665505144 is a wasteful number, since it uses less digits than its factorization.

665505144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645 (or 638 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The square root of 665505144 is about 25797.3863792439. The cubic root of 665505144 is about 873.0728280508.

The spelling of 665505144 in words is "six hundred sixty-five million, five hundred five thousand, one hundred forty-four".