865826720 has 192 divisors, whose sum is σ = 2368445184. Its totient is φ = 296017920.

The previous prime is 865826719. The next prime is 865826723. The reversal of 865826720 is 27628568.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is not an unprimeable number, because it can be changed into a prime (865826723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2954894 + ... + 2955186.

It is an arithmetic number, because the mean of its divisors is an integer number (12335652).

Almost surely, 2^865826720 is an apocalyptic number.

865826720 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 865826720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1184222592).

865826720 is an abundant number, since it is smaller than the sum of its proper divisors (1502618464).

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

865826720 is a wasteful number, since it uses less digits than its factorization.

865826720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 407 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 44.

The square root of 865826720 is about 29424.9336447850. The cubic root of 865826720 is about 953.1113941550. Note that the first 3 decimals are identical.

The spelling of 865826720 in words is "eight hundred sixty-five million, eight hundred twenty-six thousand, seven hundred twenty".