208687949 has 2 divisors, whose sum is σ = 208687950. Its totient is φ = 208687948.

The previous prime is 208687931. The next prime is 208687981. The reversal of 208687949 is 949786802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 107785924 + 100902025 = 10382^2 + 10045^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208687949 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 208687949.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208687249) 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, 104343974 + 104343975.

It is an arithmetic number, because the mean of its divisors is an integer number (104343975).

Almost surely, 2^208687949 is an apocalyptic number.

It is an amenable number.

208687949 is a deficient number, since it is larger than the sum of its proper divisors (1).

208687949 is an equidigital number, since it uses as much as digits as its factorization.

208687949 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1741824, while the sum is 53.

The square root of 208687949 is about 14446.0357537976. The cubic root of 208687949 is about 593.1517147768.

The spelling of 208687949 in words is "two hundred eight million, six hundred eighty-seven thousand, nine hundred forty-nine".