6407920 has 40 divisors (see below), whose sum is σ = 15016896. Its totient is φ = 2542848.

The previous prime is 6407899. The next prime is 6407923. The reversal of 6407920 is 297046.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-3 number, since 3×6407920³ (a number of 21 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

6407920 is a modest number, since divided by 7920 gives 640 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6407923) 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, 13609 + ... + 14071.

Almost surely, 2^6407920 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6407920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7508448).

6407920 is an abundant number, since it is smaller than the sum of its proper divisors (8608976).

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

6407920 is a wasteful number, since it uses less digits than its factorization.

6407920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649 (or 643 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 28.

The square root of 6407920 is about 2531.3869716027. The cubic root of 6407920 is about 185.7401079902.

The spelling of 6407920 in words is "six million, four hundred seven thousand, nine hundred twenty".