6561567 has 20 divisors (see below), whose sum is σ = 9975240. Its totient is φ = 4297104.

The previous prime is 6561557. The next prime is 6561589. The reversal of 6561567 is 7651656.

It is a happy number.

It is not a de Polignac number, because 6561567 - 2⁴ = 6561551 is a prime.

It is a super-2 number, since 2×6561567² = 86108322990978, which contains 22 as substring.

It is an Ulam number.

6561567 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4093 + ... + 5465.

It is an arithmetic number, because the mean of its divisors is an integer number (498762).

Almost surely, 2^6561567 is an apocalyptic number.

6561567 is a deficient number, since it is larger than the sum of its proper divisors (3413673).

6561567 is a wasteful number, since it uses less digits than its factorization.

6561567 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444 (or 1435 counting only the distinct ones).

The product of its digits is 37800, while the sum is 36.

The square root of 6561567 is about 2561.5555820634. Note that the first 4 decimals coincide. The cubic root of 6561567 is about 187.2129367292.

The spelling of 6561567 in words is "six million, five hundred sixty-one thousand, five hundred sixty-seven".