208189561 has 2 divisors, whose sum is σ = 208189562. Its totient is φ = 208189560.

The previous prime is 208189547. The next prime is 208189609. The reversal of 208189561 is 165981802.

208189561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 192349161 + 15840400 = 13869^2 + 3980^2 .

It is a cyclic number.

It is not a de Polignac number, because 208189561 - 2¹⁷ = 208058489 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (208189511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104094780 + 104094781.

It is an arithmetic number, because the mean of its divisors is an integer number (104094781).

Almost surely, 2^208189561 is an apocalyptic number.

It is an amenable number.

208189561 is a deficient number, since it is larger than the sum of its proper divisors (1).

208189561 is an equidigital number, since it uses as much as digits as its factorization.

208189561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34560, while the sum is 40.

The square root of 208189561 is about 14428.7754504670. The cubic root of 208189561 is about 592.6791506067.

The spelling of 208189561 in words is "two hundred eight million, one hundred eighty-nine thousand, five hundred sixty-one".