820860672 has 144 divisors (see below), whose sum is σ = 2266387200. Its totient is φ = 263577600.

The previous prime is 820860653. The next prime is 820860673. The reversal of 820860672 is 276068028.

It is a self number, because there is not a number n which added to its sum of digits gives 820860672.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820860673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4124829 + ... + 4125027.

It is an arithmetic number, because the mean of its divisors is an integer number (15738800).

Almost surely, 2^820860672 is an apocalyptic number.

820860672 is a gapful number since it is divisible by the number (82) 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 820860672, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1133193600).

820860672 is an abundant number, since it is smaller than the sum of its proper divisors (1445526528).

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

820860672 is a wasteful number, since it uses less digits than its factorization.

820860672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 390 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 820860672 is about 28650.6661702656. Note that the first 3 decimals coincide. The cubic root of 820860672 is about 936.3175195675.

The spelling of 820860672 in words is "eight hundred twenty million, eight hundred sixty thousand, six hundred seventy-two".