820791040 has 72 divisors (see below), whose sum is σ = 1991183040. Its totient is φ = 324120576.

The previous prime is 820791029. The next prime is 820791053. The reversal of 820791040 is 40197028.

It is a junction number, because it is equal to n+sod(n) for n = 820790993 and 820791011.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97062 + ... + 105178.

It is an arithmetic number, because the mean of its divisors is an integer number (27655320).

Almost surely, 2^820791040 is an apocalyptic number.

820791040 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 820791040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (995591520).

820791040 is an abundant number, since it is smaller than the sum of its proper divisors (1170392000).

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

820791040 is an equidigital number, since it uses as much as digits as its factorization.

820791040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8217 (or 8203 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 31.

The square root of 820791040 is about 28649.4509545995. The cubic root of 820791040 is about 936.2910434930.

The spelling of 820791040 in words is "eight hundred twenty million, seven hundred ninety-one thousand, forty".