6646869720 has 160 divisors (see below), whose sum is σ = 22816728000. Its totient is φ = 1734746112.

The previous prime is 6646869709. The next prime is 6646869721. The reversal of 6646869720 is 279686466.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6646869721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 130456 + ... + 174104.

It is an arithmetic number, because the mean of its divisors is an integer number (142604550).

Almost surely, 2^6646869720 is an apocalyptic number.

6646869720 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 6646869720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (11408364000).

6646869720 is an abundant number, since it is smaller than the sum of its proper divisors (16169858280).

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

6646869720 is a wasteful number, since it uses less digits than its factorization.

6646869720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43719 (or 43706 counting only the distinct ones).

The product of its (nonzero) digits is 5225472, while the sum is 54.

The square root of 6646869720 is about 81528.3369142288. The cubic root of 6646869720 is about 1880.2072466563.

The spelling of 6646869720 in words is "six billion, six hundred forty-six million, eight hundred sixty-nine thousand, seven hundred twenty".