665261044 has 36 divisors (see below), whose sum is σ = 1400992740. Its totient is φ = 275278080.

The previous prime is 665261029. The next prime is 665261053. The reversal of 665261044 is 440162566.

It can be written as a sum of positive squares in 2 ways, for example, as 361456144 + 303804900 = 19012^2 + 17430^2 .

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 52837 + ... + 64204.

It is an arithmetic number, because the mean of its divisors is an integer number (38916465).

Almost surely, 2^665261044 is an apocalyptic number.

It is an amenable number.

665261044 is an abundant number, since it is smaller than the sum of its proper divisors (735731696).

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

665261044 is a wasteful number, since it uses less digits than its factorization.

665261044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117088 (or 117079 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 34.

The square root of 665261044 is about 25792.6548459053. The cubic root of 665261044 is about 872.9660704793.

The spelling of 665261044 in words is "six hundred sixty-five million, two hundred sixty-one thousand, forty-four".