8428240 has 40 divisors (see below), whose sum is σ = 19764360. Its totient is φ = 3342336.

The previous prime is 8428237. The next prime is 8428289. The reversal of 8428240 is 428248.

It can be written as a sum of positive squares in 4 ways, for example, as 788544 + 7639696 = 888^2 + 2764^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a junction number, because it is equal to n+sod(n) for n = 8428199 and 8428208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10576 + ... + 11344.

It is an arithmetic number, because the mean of its divisors is an integer number (494109).

Almost surely, 2^8428240 is an apocalyptic number.

8428240 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 8428240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9882180).

8428240 is an abundant number, since it is smaller than the sum of its proper divisors (11336120).

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

8428240 is a wasteful number, since it uses less digits than its factorization.

8428240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919 (or 913 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 28.

The square root of 8428240 is about 2903.1431242707. The cubic root of 8428240 is about 203.5068184061.

It can be divided in two parts, 8428 and 240, that added together give a palindrome (8668).

The spelling of 8428240 in words is "eight million, four hundred twenty-eight thousand, two hundred forty".