85840640 has 72 divisors (see below), whose sum is σ = 207261600. Its totient is φ = 34062336.

The previous prime is 85840639. The next prime is 85840649. The reversal of 85840640 is 4604858.

It is a self number, because there is not a number n which added to its sum of digits gives 85840640.

It is not an unprimeable number, because it can be changed into a prime (85840649) 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, 254552 + ... + 254888.

Almost surely, 2^85840640 is an apocalyptic number.

85840640 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 85840640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (103630800).

85840640 is an abundant number, since it is smaller than the sum of its proper divisors (121420960).

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

85840640 is a wasteful number, since it uses less digits than its factorization.

85840640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 557 (or 543 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 35.

The square root of 85840640 is about 9265.0223960873. The cubic root of 85840640 is about 441.1276858719.

The spelling of 85840640 in words is "eighty-five million, eight hundred forty thousand, six hundred forty".