6420864 has 64 divisors (see below), whose sum is σ = 17821440. Its totient is φ = 2044416.

The previous prime is 6420853. The next prime is 6420877. The reversal of 6420864 is 4680246.

It is a tau number, because it is divible by the number of its divisors (64).

It is a zygodrome in base 2.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8469 + ... + 9195.

It is an arithmetic number, because the mean of its divisors is an integer number (278460).

Almost surely, 2^6420864 is an apocalyptic number.

6420864 is a gapful number since it is divisible by the number (64) 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 6420864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8910720).

6420864 is an abundant number, since it is smaller than the sum of its proper divisors (11400576).

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

6420864 is a wasteful number, since it uses less digits than its factorization.

6420864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767 (or 755 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 30.

The square root of 6420864 is about 2533.9423829282. The cubic root of 6420864 is about 185.8650888956.

The spelling of 6420864 in words is "six million, four hundred twenty thousand, eight hundred sixty-four".