6820664400 has 240 divisors, whose sum is σ = 26483929920. Its totient is φ = 1653465600.

The previous prime is 6820664381. The next prime is 6820664437. The reversal of 6820664400 is 44660286.

It is a happy number.

6820664400 is a `hidden beast` number, since 6 + 8 + 2 + 0 + 6 + 644 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (240).

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 (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 90094 + ... + 147506.

It is an arithmetic number, because the mean of its divisors is an integer number (110349708).

Almost surely, 2^6820664400 is an apocalyptic number.

6820664400 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 6820664400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13241964960).

6820664400 is an abundant number, since it is smaller than the sum of its proper divisors (19663265520).

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

6820664400 is a wasteful number, since it uses less digits than its factorization.

6820664400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 57451 (or 57434 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 36.

The square root of 6820664400 is about 82587.3137957641. The cubic root of 6820664400 is about 1896.4536248360.

The spelling of 6820664400 in words is "six billion, eight hundred twenty million, six hundred sixty-four thousand, four hundred".