16561187 has 2 divisors, whose sum is σ = 16561188. Its totient is φ = 16561186.

The previous prime is 16561169. The next prime is 16561189. The reversal of 16561187 is 78116561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16561187 - 2¹⁰ = 16560163 is a prime.

Together with 16561189, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (16561189) 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, 8280593 + 8280594.

It is an arithmetic number, because the mean of its divisors is an integer number (8280594).

Almost surely, 2^16561187 is an apocalyptic number.

16561187 is a deficient number, since it is larger than the sum of its proper divisors (1).

16561187 is an equidigital number, since it uses as much as digits as its factorization.

16561187 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 10080, while the sum is 35.

The square root of 16561187 is about 4069.5438319301. The cubic root of 16561187 is about 254.8964695703.

The spelling of 16561187 in words is "sixteen million, five hundred sixty-one thousand, one hundred eighty-seven".