665318544 has 80 divisors (see below), whose sum is σ = 1882171200. Its totient is φ = 200839680.

The previous prime is 665318531. The next prime is 665318557. The reversal of 665318544 is 445813566.

It is an interprime number because it is at equal distance from previous prime (665318531) and next prime (665318557).

It is a junction number, because it is equal to n+sod(n) for n = 665318496 and 665318505.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143982 + ... + 148530.

It is an arithmetic number, because the mean of its divisors is an integer number (23527140).

Almost surely, 2^665318544 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 665318544, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (941085600).

665318544 is an abundant number, since it is smaller than the sum of its proper divisors (1216852656).

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

665318544 is a wasteful number, since it uses less digits than its factorization.

665318544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4848 (or 4842 counting only the distinct ones).

The product of its digits is 345600, while the sum is 42.

The square root of 665318544 is about 25793.7694802446. The cubic root of 665318544 is about 872.9912205581.

The spelling of 665318544 in words is "six hundred sixty-five million, three hundred eighteen thousand, five hundred forty-four".