821056680 has 96 divisors (see below), whose sum is σ = 2673833760. Its totient is φ = 218505600.

The previous prime is 821056679. The next prime is 821056681. The reversal of 821056680 is 86650128.

It is a happy number.

821056680 is a `hidden beast` number, since 8 + 2 + 10 + 566 + 80 = 666.

It is an interprime number because it is at equal distance from previous prime (821056679) and next prime (821056681).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (821056681) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 200655 + ... + 204705.

It is an arithmetic number, because the mean of its divisors is an integer number (27852435).

Almost surely, 2^821056680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 821056680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1336916880).

821056680 is an abundant number, since it is smaller than the sum of its proper divisors (1852777080).

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

821056680 is a wasteful number, since it uses less digits than its factorization.

821056680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4631 (or 4624 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 821056680 is about 28654.0866195382. The cubic root of 821056680 is about 936.3920393673.

The spelling of 821056680 in words is "eight hundred twenty-one million, fifty-six thousand, six hundred eighty".