208721873 has 2 divisors, whose sum is σ = 208721874. Its totient is φ = 208721872.

The previous prime is 208721837. The next prime is 208721911. The reversal of 208721873 is 378127802.

Together with previous prime (208721837) it forms an Ormiston pair, because they use the same digits, order apart.

It is an a-pointer prime, because the next prime (208721911) can be obtained adding 208721873 to its sum of digits (38).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 156550144 + 52171729 = 12512^2 + 7223^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208721873 is a prime.

It is not a weakly prime, because it can be changed into another prime (208721813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104360936 + 104360937.

It is an arithmetic number, because the mean of its divisors is an integer number (104360937).

Almost surely, 2^208721873 is an apocalyptic number.

It is an amenable number.

208721873 is a deficient number, since it is larger than the sum of its proper divisors (1).

208721873 is an equidigital number, since it uses as much as digits as its factorization.

208721873 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 37632, while the sum is 38.

The square root of 208721873 is about 14447.2098690370. The cubic root of 208721873 is about 593.1838536531.

The spelling of 208721873 in words is "two hundred eight million, seven hundred twenty-one thousand, eight hundred seventy-three".