208506913 has 2 divisors, whose sum is σ = 208506914. Its totient is φ = 208506912.

The previous prime is 208506901. The next prime is 208506919. The reversal of 208506913 is 319605802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171819664 + 36687249 = 13108^2 + 6057^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208506913 is a prime.

It is not a weakly prime, because it can be changed into another prime (208506919) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104253456 + 104253457.

It is an arithmetic number, because the mean of its divisors is an integer number (104253457).

Almost surely, 2^208506913 is an apocalyptic number.

It is an amenable number.

208506913 is a deficient number, since it is larger than the sum of its proper divisors (1).

208506913 is an equidigital number, since it uses as much as digits as its factorization.

208506913 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 208506913 is about 14439.7684538222. The cubic root of 208506913 is about 592.9801462052.

The spelling of 208506913 in words is "two hundred eight million, five hundred six thousand, nine hundred thirteen".