860821920 has 576 divisors, whose sum is σ = 3622993920. Its totient is φ = 181868544.

The previous prime is 860821903. The next prime is 860821921. The reversal of 860821920 is 29128068.

860821920 is a `hidden beast` number, since 8 + 608 + 21 + 9 + 20 = 666.

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 (860821921) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 10896441 + ... + 10896519.

It is an arithmetic number, because the mean of its divisors is an integer number (6289920).

Almost surely, 2^860821920 is an apocalyptic number.

860821920 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 860821920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1811496960).

860821920 is an abundant number, since it is smaller than the sum of its proper divisors (2762172000).

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

860821920 is a wasteful number, since it uses less digits than its factorization.

860821920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177 (or 166 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 860821920 is about 29339.7668702394. The cubic root of 860821920 is about 951.2713983570.

Adding to 860821920 its reverse (29128068), we get a palindrome (889949988).

The spelling of 860821920 in words is "eight hundred sixty million, eight hundred twenty-one thousand, nine hundred twenty".