665757660 has 96 divisors (see below), whose sum is σ = 1914502464. Its totient is φ = 172800000.

The previous prime is 665757649. The next prime is 665757709. The reversal of 665757660 is 66757566.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 368760 + ... + 370560.

It is an arithmetic number, because the mean of its divisors is an integer number (19942734).

Almost surely, 2^665757660 is an apocalyptic number.

665757660 is a gapful number since it is divisible by the number (60) 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 665757660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (957251232).

665757660 is an abundant number, since it is smaller than the sum of its proper divisors (1248744804).

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

665757660 is a wasteful number, since it uses less digits than its factorization.

665757660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1975 (or 1973 counting only the distinct ones).

The product of its (nonzero) digits is 1587600, while the sum is 48.

The square root of 665757660 is about 25802.2801318023. The cubic root of 665757660 is about 873.1832389079.

The spelling of 665757660 in words is "six hundred sixty-five million, seven hundred fifty-seven thousand, six hundred sixty".