6420880 has 40 divisors (see below), whose sum is σ = 15124032. Its totient is φ = 2534784.

The previous prime is 6420877. The next prime is 6420881. The reversal of 6420880 is 880246.

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

It is not an unprimeable number, because it can be changed into a prime (6420881) 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, 6157 + ... + 7123.

Almost surely, 2^6420880 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 6420880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7562016).

6420880 is an abundant number, since it is smaller than the sum of its proper divisors (8703152).

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

6420880 is a wasteful number, since it uses less digits than its factorization.

6420880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1063 (or 1057 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 28.

The square root of 6420880 is about 2533.9455400620. The cubic root of 6420880 is about 185.8652432797.

The spelling of 6420880 in words is "six million, four hundred twenty thousand, eight hundred eighty".