208931117 has 2 divisors, whose sum is σ = 208931118. Its totient is φ = 208931116.

The previous prime is 208931083. The next prime is 208931131. The reversal of 208931117 is 711139802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192071881 + 16859236 = 13859^2 + 4106^2 .

It is a cyclic number.

It is not a de Polignac number, because 208931117 - 2⁶ = 208931053 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208931137) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104465558 + 104465559.

It is an arithmetic number, because the mean of its divisors is an integer number (104465559).

Almost surely, 2^208931117 is an apocalyptic number.

It is an amenable number.

208931117 is a deficient number, since it is larger than the sum of its proper divisors (1).

208931117 is an equidigital number, since it uses as much as digits as its factorization.

208931117 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024, while the sum is 32.

The square root of 208931117 is about 14454.4497301004. The cubic root of 208931117 is about 593.3820100269.

The spelling of 208931117 in words is "two hundred eight million, nine hundred thirty-one thousand, one hundred seventeen".