6561558 has 48 divisors (see below), whose sum is σ = 15449616. Its totient is φ = 2004480.

The previous prime is 6561557. The next prime is 6561589. The reversal of 6561558 is 8551656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561551) 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 23 ways as a sum of consecutive naturals, for example, 12285 + ... + 12807.

It is an arithmetic number, because the mean of its divisors is an integer number (321867).

Almost surely, 2^6561558 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6561558, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (7724808).

6561558 is an abundant number, since it is smaller than the sum of its proper divisors (8888058).

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

6561558 is a wasteful number, since it uses less digits than its factorization.

6561558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 589 (or 586 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 6561558 is about 2561.5538253178. The cubic root of 6561558 is about 187.2128511340.

The spelling of 6561558 in words is "six million, five hundred sixty-one thousand, five hundred fifty-eight".