665495872 has 56 divisors (see below), whose sum is σ = 1410910056. Its totient is φ = 310345728.

The previous prime is 665495867. The next prime is 665495917. The reversal of 665495872 is 278594566.

It can be written as a sum of positive squares in 4 ways, for example, as 2742336 + 662753536 = 1656^2 + 25744^2 .

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 120238 + ... + 125650.

Almost surely, 2^665495872 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 665495872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (705455028).

665495872 is an abundant number, since it is smaller than the sum of its proper divisors (745414184).

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

665495872 is a wasteful number, since it uses less digits than its factorization.

665495872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5555 (or 5545 counting only the distinct ones).

The product of its digits is 3628800, while the sum is 52.

The square root of 665495872 is about 25797.2066704905. The cubic root of 665495872 is about 873.0687734020.

The spelling of 665495872 in words is "six hundred sixty-five million, four hundred ninety-five thousand, eight hundred seventy-two".