208842561 has 24 divisors (see below), whose sum is σ = 313292616. Its totient is φ = 133954560.

The previous prime is 208842559. The next prime is 208842577. The reversal of 208842561 is 165248802.

208842561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 48566961 + 160275600 = 6969^2 + 12660^2 .

It is not a de Polignac number, because 208842561 - 2¹ = 208842559 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (208842511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 23061 + ... + 30813.

It is an arithmetic number, because the mean of its divisors is an integer number (13053859).

Almost surely, 2^208842561 is an apocalyptic number.

It is an amenable number.

208842561 is a deficient number, since it is larger than the sum of its proper divisors (104450055).

208842561 is a wasteful number, since it uses less digits than its factorization.

208842561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7873 (or 7870 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 208842561 is about 14451.3861272890. The cubic root of 208842561 is about 593.2981626742.

The spelling of 208842561 in words is "two hundred eight million, eight hundred forty-two thousand, five hundred sixty-one".