820705987080 has 640 divisors, whose sum is σ = 3262887936000. Its totient is φ = 181057006080.

The previous prime is 820705986983. The next prime is 820705987081. The reversal of 820705987080 is 80789507028.

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 (820705987081) by changing a digit.

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 159 ways as a sum of consecutive naturals, for example, 308650791 + ... + 308653449.

It is an arithmetic number, because the mean of its divisors is an integer number (5098262400).

Almost surely, 2^820705987080 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 820705987080, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1631443968000).

820705987080 is an abundant number, since it is smaller than the sum of its proper divisors (2442181948920).

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

820705987080 is a wasteful number, since it uses less digits than its factorization.

820705987080 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3159 (or 3146 counting only the distinct ones).

The product of its (nonzero) digits is 2257920, while the sum is 54.

The spelling of 820705987080 in words is "eight hundred twenty billion, seven hundred five million, nine hundred eighty-seven thousand, eighty".