8440020 has 36 divisors (see below), whose sum is σ = 25601940. Its totient is φ = 2250624.

The previous prime is 8439989. The next prime is 8440031. The reversal of 8440020 is 200448.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 3617604 + 4822416 = 1902^2 + 2196^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 8439975 and 8440002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 23265 + ... + 23624.

It is an arithmetic number, because the mean of its divisors is an integer number (711165).

Almost surely, 2^8440020 is an apocalyptic number.

It is an amenable number.

8440020 is an abundant number, since it is smaller than the sum of its proper divisors (17161920).

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

8440020 is a wasteful number, since it uses less digits than its factorization.

8440020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46904 (or 46899 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 18.

The square root of 8440020 is about 2905.1712514067. The cubic root of 8440020 is about 203.6015868787.

Adding to 8440020 its reverse (200448), we get a palindrome (8640468).

It can be divided in two parts, 84 and 40020, that added together give a palindrome (40104).

The spelling of 8440020 in words is "eight million, four hundred forty thousand, twenty".