208890257 has 2 divisors, whose sum is σ = 208890258. Its totient is φ = 208890256.

The previous prime is 208890223. The next prime is 208890281. The reversal of 208890257 is 752098802.

It is a happy number.

208890257 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 208629136 + 261121 = 14444^2 + 511^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208890257 is a prime.

It is not a weakly prime, because it can be changed into another prime (208890287) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104445128 + 104445129.

It is an arithmetic number, because the mean of its divisors is an integer number (104445129).

Almost surely, 2^208890257 is an apocalyptic number.

It is an amenable number.

208890257 is a deficient number, since it is larger than the sum of its proper divisors (1).

208890257 is an equidigital number, since it uses as much as digits as its factorization.

208890257 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80640, while the sum is 41.

The square root of 208890257 is about 14453.0362554032. The cubic root of 208890257 is about 593.3433255552.

The spelling of 208890257 in words is "two hundred eight million, eight hundred ninety thousand, two hundred fifty-seven".