6420040 has 32 divisors (see below), whose sum is σ = 15759360. Its totient is φ = 2334400.

The previous prime is 6420031. The next prime is 6420041. The reversal of 6420040 is 400246.

It is an Ulam number.

It is a junction number, because it is equal to n+sod(n) for n = 6419996 and 6420023.

It is not an unprimeable number, because it can be changed into a prime (6420041) 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 7 ways as a sum of consecutive naturals, for example, 6856 + ... + 7735.

It is an arithmetic number, because the mean of its divisors is an integer number (492480).

Almost surely, 2^6420040 is an apocalyptic number.

It is an amenable number.

6420040 is an abundant number, since it is smaller than the sum of its proper divisors (9339320).

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

6420040 is a wasteful number, since it uses less digits than its factorization.

6420040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14613 (or 14609 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 6420040 is about 2533.7797852221. The cubic root of 6420040 is about 185.8571377650.

Adding to 6420040 its reverse (400246), we get a palindrome (6820286).

The spelling of 6420040 in words is "six million, four hundred twenty thousand, forty".