16561166 has 4 divisors (see below), whose sum is σ = 24841752. Its totient is φ = 8280582.

The previous prime is 16561157. The next prime is 16561169. The reversal of 16561166 is 66116561.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561169) 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 as a sum of consecutive naturals, namely, 4140290 + ... + 4140293.

It is an arithmetic number, because the mean of its divisors is an integer number (6210438).

Almost surely, 2^16561166 is an apocalyptic number.

16561166 is a deficient number, since it is larger than the sum of its proper divisors (8280586).

16561166 is an equidigital number, since it uses as much as digits as its factorization.

16561166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8280585.

The product of its digits is 6480, while the sum is 32.

The square root of 16561166 is about 4069.5412517875. The cubic root of 16561166 is about 254.8963618318.

The spelling of 16561166 in words is "sixteen million, five hundred sixty-one thousand, one hundred sixty-six".