85728640 has 128 divisors (see below), whose sum is σ = 220320000. Its totient is φ = 31825920.

The previous prime is 85728623. The next prime is 85728641. The reversal of 85728640 is 4682758.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 85728593 and 85728602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (85728641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 575286 + ... + 575434.

It is an arithmetic number, because the mean of its divisors is an integer number (1721250).

Almost surely, 2^85728640 is an apocalyptic number.

85728640 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 85728640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110160000).

85728640 is an abundant number, since it is smaller than the sum of its proper divisors (134591360).

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

85728640 is a wasteful number, since it uses less digits than its factorization.

85728640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 228 (or 216 counting only the distinct ones).

The product of its (nonzero) digits is 107520, while the sum is 40.

The square root of 85728640 is about 9258.9761853026. The cubic root of 85728640 is about 440.9357495741.

It can be divided in two parts, 85728 and 640, that added together give a palindrome (86368).

The spelling of 85728640 in words is "eighty-five million, seven hundred twenty-eight thousand, six hundred forty".