6405660 has 72 divisors (see below), whose sum is σ = 20464080. Its totient is φ = 1617408.

The previous prime is 6405653. The next prime is 6405701. The reversal of 6405660 is 665046.

6405660 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2484 + ... + 4356.

Almost surely, 2^6405660 is an apocalyptic number.

6405660 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 6405660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (10232040).

6405660 is an abundant number, since it is smaller than the sum of its proper divisors (14058420).

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

6405660 is a wasteful number, since it uses less digits than its factorization.

6405660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1907 (or 1902 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 6405660 is about 2530.9405366385. The cubic root of 6405660 is about 185.7182692862.

The spelling of 6405660 in words is "six million, four hundred five thousand, six hundred sixty".