6404520 has 96 divisors (see below), whose sum is σ = 20613600. Its totient is φ = 1587456.

The previous prime is 6404477. The next prime is 6404521. The reversal of 6404520 is 254046.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (6404521) 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 23 ways as a sum of consecutive naturals, for example, 120814 + ... + 120866.

It is an arithmetic number, because the mean of its divisors is an integer number (214725).

Almost surely, 2^6404520 is an apocalyptic number.

6404520 is a gapful number since it is divisible by the number (60) 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 6404520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10306800).

6404520 is an abundant number, since it is smaller than the sum of its proper divisors (14209080).

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

6404520 is a wasteful number, since it uses less digits than its factorization.

6404520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 21.

The square root of 6404520 is about 2530.7153138984. The cubic root of 6404520 is about 185.7072513537.

Adding to 6404520 its reverse (254046), we get a palindrome (6658566).

The spelling of 6404520 in words is "six million, four hundred four thousand, five hundred twenty".