665128560 has 80 divisors (see below), whose sum is σ = 2128435200. Its totient is φ = 171644160.

The previous prime is 665128523. The next prime is 665128603. The reversal of 665128560 is 65821566.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

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, 37260 + ... + 52139.

It is an arithmetic number, because the mean of its divisors is an integer number (26605440).

Almost surely, 2^665128560 is an apocalyptic number.

665128560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665128560 is an abundant number, since it is smaller than the sum of its proper divisors (1463306640).

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

665128560 is a wasteful number, since it uses less digits than its factorization.

665128560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89446 (or 89440 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 39.

The square root of 665128560 is about 25790.0864674782. The cubic root of 665128560 is about 872.9081174316.

The spelling of 665128560 in words is "six hundred sixty-five million, one hundred twenty-eight thousand, five hundred sixty".