665061660 has 36 divisors (see below), whose sum is σ = 2017354248. Its totient is φ = 177349728.

The previous prime is 665061637. The next prime is 665061671. The reversal of 665061660 is 66160566.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1847214 + ... + 1847573.

It is an arithmetic number, because the mean of its divisors is an integer number (56037618).

Almost surely, 2^665061660 is an apocalyptic number.

665061660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

665061660 is an abundant number, since it is smaller than the sum of its proper divisors (1352292588).

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

665061660 is a wasteful number, since it uses less digits than its factorization.

665061660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3694802 (or 3694797 counting only the distinct ones).

The product of its (nonzero) digits is 38880, while the sum is 36.

The square root of 665061660 is about 25788.7894248644. The cubic root of 665061660 is about 872.8788501518.

The spelling of 665061660 in words is "six hundred sixty-five million, sixty-one thousand, six hundred sixty".