6501660660 has 144 divisors (see below), whose sum is σ = 21705727680. Its totient is φ = 1562158080.

The previous prime is 6501660653. The next prime is 6501660703. The reversal of 6501660660 is 660661056.

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

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 209211 + ... + 238269.

It is an arithmetic number, because the mean of its divisors is an integer number (150734220).

Almost surely, 2^6501660660 is an apocalyptic number.

6501660660 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 6501660660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10852863840).

6501660660 is an abundant number, since it is smaller than the sum of its proper divisors (15204067020).

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

6501660660 is a wasteful number, since it uses less digits than its factorization.

6501660660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29198 (or 29193 counting only the distinct ones).

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

The square root of 6501660660 is about 80632.8758013752. The cubic root of 6501660660 is about 1866.4144990287.

The spelling of 6501660660 in words is "six billion, five hundred one million, six hundred sixty thousand, six hundred sixty".