6647316720 has 160 divisors (see below), whose sum is σ = 22645336320. Its totient is φ = 1599621120.

The previous prime is 6647316677. The next prime is 6647316721. The reversal of 6647316720 is 276137466.

It is a happy number.

It is a super-3 number, since 3×6647316720³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6647316721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 352491 + ... + 370869.

It is an arithmetic number, because the mean of its divisors is an integer number (141533352).

Almost surely, 2^6647316720 is an apocalyptic number.

6647316720 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 6647316720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11322668160).

6647316720 is an abundant number, since it is smaller than the sum of its proper divisors (15998019600).

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

6647316720 is a wasteful number, since it uses less digits than its factorization.

6647316720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18543 (or 18537 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 42.

The square root of 6647316720 is about 81531.0782462737. The cubic root of 6647316720 is about 1880.2493935032.

The spelling of 6647316720 in words is "six billion, six hundred forty-seven million, three hundred sixteen thousand, seven hundred twenty".