865339840 has 56 divisors (see below), whose sum is σ = 2091397392. Its totient is φ = 340961280.

The previous prime is 865339829. The next prime is 865339847. The reversal of 865339840 is 48933568.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865339847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1260 + ... + 41620.

It is an arithmetic number, because the mean of its divisors is an integer number (37346382).

Almost surely, 2^865339840 is an apocalyptic number.

865339840 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 865339840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1045698696).

865339840 is an abundant number, since it is smaller than the sum of its proper divisors (1226057552).

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

865339840 is a wasteful number, since it uses less digits than its factorization.

865339840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40445 (or 40435 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 46.

The square root of 865339840 is about 29416.6592256837. The cubic root of 865339840 is about 952.9327064048.

The spelling of 865339840 in words is "eight hundred sixty-five million, three hundred thirty-nine thousand, eight hundred forty".