865218240 has 224 divisors, whose sum is σ = 3072384000. Its totient is φ = 229211136.

The previous prime is 865218199. The next prime is 865218307. The reversal of 865218240 is 42812568.

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 = 865218195 and 865218204.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 2064751 + ... + 2065169.

It is an arithmetic number, because the mean of its divisors is an integer number (13716000).

Almost surely, 2^865218240 is an apocalyptic number.

865218240 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 865218240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1536192000).

865218240 is an abundant number, since it is smaller than the sum of its proper divisors (2207165760).

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

865218240 is a wasteful number, since it uses less digits than its factorization.

865218240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 684 (or 668 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 865218240 is about 29414.5922970216. The cubic root of 865218240 is about 952.8880680481. Note that the first 3 decimals are identical.

The spelling of 865218240 in words is "eight hundred sixty-five million, two hundred eighteen thousand, two hundred forty".