6400020 has 48 divisors (see below), whose sum is σ = 19551168. Its totient is φ = 1551360.

The previous prime is 6400019. The next prime is 6400033. The reversal of 6400020 is 200046.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 6399969 and 6400005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4189 + ... + 5508.

It is an arithmetic number, because the mean of its divisors is an integer number (407316).

Almost surely, 2^6400020 is an apocalyptic number.

6400020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

6400020 is an abundant number, since it is smaller than the sum of its proper divisors (13151148).

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

6400020 is a wasteful number, since it uses less digits than its factorization.

6400020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9720 (or 9718 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 6400020 is about 2529.8260809787. The cubic root of 6400020 is about 185.6637467438.

6400020 divided by its sum of digits (12) gives a palindrome (533335).

Adding to 6400020 its reverse (200046), we get a palindrome (6600066).

The spelling of 6400020 in words is "six million, four hundred thousand, twenty".