188566561 has 2 divisors, whose sum is σ = 188566562. Its totient is φ = 188566560.

The previous prime is 188566531. The next prime is 188566571. The reversal of 188566561 is 165665881.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 181037025 + 7529536 = 13455^2 + 2744^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-188566561 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (188566531) 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, 94283280 + 94283281.

It is an arithmetic number, because the mean of its divisors is an integer number (94283281).

Almost surely, 2^188566561 is an apocalyptic number.

It is an amenable number.

188566561 is a deficient number, since it is larger than the sum of its proper divisors (1).

188566561 is an equidigital number, since it uses as much as digits as its factorization.

188566561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 345600, while the sum is 46.

The square root of 188566561 is about 13731.9540124485. The cubic root of 188566561 is about 573.4403211720.

The spelling of 188566561 in words is "one hundred eighty-eight million, five hundred sixty-six thousand, five hundred sixty-one".