208957289 has 2 divisors, whose sum is σ = 208957290. Its totient is φ = 208957288.

The previous prime is 208957223. The next prime is 208957313. The reversal of 208957289 is 982759802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 172475689 + 36481600 = 13133^2 + 6040^2 .

It is a cyclic number.

It is not a de Polignac number, because 208957289 - 2¹² = 208953193 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (208957219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104478644 + 104478645.

It is an arithmetic number, because the mean of its divisors is an integer number (104478645).

Almost surely, 2^208957289 is an apocalyptic number.

It is an amenable number.

208957289 is a deficient number, since it is larger than the sum of its proper divisors (1).

208957289 is an equidigital number, since it uses as much as digits as its factorization.

208957289 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 50.

The square root of 208957289 is about 14455.3550285007. The cubic root of 208957289 is about 593.4067858889.

The spelling of 208957289 in words is "two hundred eight million, nine hundred fifty-seven thousand, two hundred eighty-nine".