6566561 has 4 divisors (see below), whose sum is σ = 6604692. Its totient is φ = 6528432.

The previous prime is 6566551. The next prime is 6566563. The reversal of 6566561 is 1656656.

6566561 is an esthetic number in base 15, because in such base its adjacent digits differ by 1.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2689600 + 3876961 = 1640^2 + 1969^2 .

It is a cyclic number.

It is not a de Polignac number, because 6566561 - 2¹⁴ = 6550177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (6566563) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18806 + ... + 19151.

It is an arithmetic number, because the mean of its divisors is an integer number (1651173).

Almost surely, 2^6566561 is an apocalyptic number.

It is an amenable number.

6566561 is a deficient number, since it is larger than the sum of its proper divisors (38131).

6566561 is a wasteful number, since it uses less digits than its factorization.

6566561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38130.

The product of its digits is 32400, while the sum is 35.

The square root of 6566561 is about 2562.5301949441. The cubic root of 6566561 is about 187.2604205245.

The spelling of 6566561 in words is "six million, five hundred sixty-six thousand, five hundred sixty-one".