6821929728 has 144 divisors (see below), whose sum is σ = 21360699360. Its totient is φ = 2140176384.

The previous prime is 6821929717. The next prime is 6821929729. The reversal of 6821929728 is 8279291286.

It is a tau number, because it is divible by the number of its divisors (144).

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

It is not an unprimeable number, because it can be changed into a prime (6821929729) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 88476 + ... + 146532.

It is an arithmetic number, because the mean of its divisors is an integer number (148338190).

Almost surely, 2^6821929728 is an apocalyptic number.

6821929728 is a gapful number since it is divisible by the number (68) 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 6821929728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10680349680).

6821929728 is an abundant number, since it is smaller than the sum of its proper divisors (14538769632).

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

6821929728 is a wasteful number, since it uses less digits than its factorization.

6821929728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58099 (or 58079 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 6821929728 is about 82594.9739875254. The cubic root of 6821929728 is about 1896.5708904159.

The spelling of 6821929728 in words is "six billion, eight hundred twenty-one million, nine hundred twenty-nine thousand, seven hundred twenty-eight".