820730844 has 72 divisors (see below), whose sum is σ = 2118458160. Its totient is φ = 267840000.

The previous prime is 820730843. The next prime is 820730849. The reversal of 820730844 is 448037028.

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

It is a junction number, because it is equal to n+sod(n) for n = 820730799 and 820730808.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820730843) 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, 550452 + ... + 551940.

It is an arithmetic number, because the mean of its divisors is an integer number (29423030).

Almost surely, 2^820730844 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 820730844, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1059229080).

820730844 is an abundant number, since it is smaller than the sum of its proper divisors (1297727316).

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

820730844 is a wasteful number, since it uses less digits than its factorization.

820730844 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811 (or 1806 counting only the distinct ones).

The product of its (nonzero) digits is 43008, while the sum is 36.

The square root of 820730844 is about 28648.4003741919. The cubic root of 820730844 is about 936.2681540482.

The spelling of 820730844 in words is "eight hundred twenty million, seven hundred thirty thousand, eight hundred forty-four".