665270784 has 120 divisors (see below), whose sum is σ = 1953357120. Its totient is φ = 217909248.

The previous prime is 665270783. The next prime is 665270803. The reversal of 665270784 is 487072566.

It is not an unprimeable number, because it can be changed into a prime (665270783) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 270649 + ... + 273095.

It is an arithmetic number, because the mean of its divisors is an integer number (16277976).

Almost surely, 2^665270784 is an apocalyptic number.

665270784 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665270784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (976678560).

665270784 is an abundant number, since it is smaller than the sum of its proper divisors (1288086336).

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

665270784 is a wasteful number, since it uses less digits than its factorization.

665270784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2530 (or 2511 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The square root of 665270784 is about 25792.8436586585. The cubic root of 665270784 is about 872.9703307859.

The spelling of 665270784 in words is "six hundred sixty-five million, two hundred seventy thousand, seven hundred eighty-four".