821678860800 has 480 divisors, whose sum is σ = 3446822544000. Its totient is φ = 187811758080.

The previous prime is 821678860787. The next prime is 821678860817. The reversal of 821678860800 is 8068876128.

821678860800 is a `hidden beast` number, since 8 + 21 + 6 + 7 + 8 + 8 + 608 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2249376 + ... + 2589024.

It is an arithmetic number, because the mean of its divisors is an integer number (7180880300).

Almost surely, 2^821678860800 is an apocalyptic number.

821678860800 is a gapful number since it is divisible by the number (80) 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 821678860800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1723411272000).

821678860800 is an abundant number, since it is smaller than the sum of its proper divisors (2625143683200).

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

821678860800 is a wasteful number, since it uses less digits than its factorization.

821678860800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339693 (or 339666 counting only the distinct ones).

The product of its (nonzero) digits is 2064384, while the sum is 54.

The spelling of 821678860800 in words is "eight hundred twenty-one billion, six hundred seventy-eight million, eight hundred sixty thousand, eight hundred".