208427561 has 2 divisors, whose sum is σ = 208427562. Its totient is φ = 208427560.

The previous prime is 208427543. The next prime is 208427573. The reversal of 208427561 is 165724802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179051161 + 29376400 = 13381^2 + 5420^2 .

It is a cyclic number.

It is not a de Polignac number, because 208427561 - 2¹⁸ = 208165417 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (208427591) 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, 104213780 + 104213781.

It is an arithmetic number, because the mean of its divisors is an integer number (104213781).

Almost surely, 2^208427561 is an apocalyptic number.

It is an amenable number.

208427561 is a deficient number, since it is larger than the sum of its proper divisors (1).

208427561 is an equidigital number, since it uses as much as digits as its factorization.

208427561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 208427561 is about 14437.0205028600. The cubic root of 208427561 is about 592.9049126789.

The spelling of 208427561 in words is "two hundred eight million, four hundred twenty-seven thousand, five hundred sixty-one".