6420660 has 48 divisors (see below), whose sum is σ = 18156096. Its totient is φ = 1695232.

The previous prime is 6420599. The next prime is 6420683. The reversal of 6420660 is 660246.

6420660 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 6420660.

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, 6307 + ... + 7253.

It is an arithmetic number, because the mean of its divisors is an integer number (378252).

Almost surely, 2^6420660 is an apocalyptic number.

6420660 is a gapful number since it is divisible by the number (60) 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 6420660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9078048).

6420660 is an abundant number, since it is smaller than the sum of its proper divisors (11735436).

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

6420660 is a wasteful number, since it uses less digits than its factorization.

6420660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1072 (or 1070 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 6420660 is about 2533.9021291281. The cubic root of 6420660 is about 185.8631204751.

The spelling of 6420660 in words is "six million, four hundred twenty thousand, six hundred sixty".