8638240 has 48 divisors (see below), whose sum is σ = 21982968. Its totient is φ = 3188736.

The previous prime is 8638237. The next prime is 8638241. The reversal of 8638240 is 428368.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 2547216 + 6091024 = 1596^2 + 2468^2 .

It is not an unprimeable number, because it can be changed into a prime (8638241) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4 + ... + 4156.

Almost surely, 2^8638240 is an apocalyptic number.

8638240 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 8638240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10991484).

8638240 is an abundant number, since it is smaller than the sum of its proper divisors (13344728).

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

8638240 is a wasteful number, since it uses less digits than its factorization.

8638240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4181 (or 4173 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 8638240 is about 2939.0882940123. The cubic root of 8638240 is about 205.1831795177.

The spelling of 8638240 in words is "eight million, six hundred thirty-eight thousand, two hundred forty".