6561166 has 4 divisors (see below), whose sum is σ = 9841752. Its totient is φ = 3280582.

The previous prime is 6561161. The next prime is 6561193. The reversal of 6561166 is 6611656.

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

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6561161) 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 as a sum of consecutive naturals, namely, 1640290 + ... + 1640293.

It is an arithmetic number, because the mean of its divisors is an integer number (2460438).

Almost surely, 2^6561166 is an apocalyptic number.

6561166 is a deficient number, since it is larger than the sum of its proper divisors (3280586).

6561166 is a wasteful number, since it uses less digits than its factorization.

6561166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3280585.

The product of its digits is 6480, while the sum is 31.

The square root of 6561166 is about 2561.4773081173. The cubic root of 6561166 is about 187.2091229087.

The spelling of 6561166 in words is "six million, five hundred sixty-one thousand, one hundred sixty-six".