6651445680 has 320 divisors, whose sum is σ = 25109821440. Its totient is φ = 1604966400.

The previous prime is 6651445667. The next prime is 6651445709. The reversal of 6651445680 is 865441566.

6651445680 is a `hidden beast` number, since 6 + 6 + 514 + 4 + 56 + 80 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6438444 + ... + 6439476.

It is an arithmetic number, because the mean of its divisors is an integer number (78468192).

Almost surely, 2^6651445680 is an apocalyptic number.

6651445680 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 6651445680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12554910720).

6651445680 is an abundant number, since it is smaller than the sum of its proper divisors (18458375760).

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

6651445680 is a wasteful number, since it uses less digits than its factorization.

6651445680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1337 (or 1325 counting only the distinct ones).

The product of its (nonzero) digits is 691200, while the sum is 45.

The square root of 6651445680 is about 81556.3957026057. The cubic root of 6651445680 is about 1880.6386166036.

The spelling of 6651445680 in words is "six billion, six hundred fifty-one million, four hundred forty-five thousand, six hundred eighty".