660565720 has 16 divisors (see below), whose sum is σ = 1486272960. Its totient is φ = 264226272.

The previous prime is 660565691. The next prime is 660565729. The reversal of 660565720 is 27565066.

It is a self number, because there is not a number n which added to its sum of digits gives 660565720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (660565729) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 8257032 + ... + 8257111.

It is an arithmetic number, because the mean of its divisors is an integer number (92892060).

Almost surely, 2^660565720 is an apocalyptic number.

It is an amenable number.

660565720 is an abundant number, since it is smaller than the sum of its proper divisors (825707240).

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

660565720 is a wasteful number, since it uses less digits than its factorization.

660565720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16514154 (or 16514150 counting only the distinct ones).

The product of its (nonzero) digits is 75600, while the sum is 37.

The square root of 660565720 is about 25701.4731095321. The cubic root of 660565720 is about 870.9074602366.

The spelling of 660565720 in words is "six hundred sixty million, five hundred sixty-five thousand, seven hundred twenty".