208918906549 has 2 divisors, whose sum is σ = 208918906550. Its totient is φ = 208918906548.

The previous prime is 208918906541. The next prime is 208918906579. The reversal of 208918906549 is 945609819802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 194705975025 + 14212931524 = 441255^2 + 119218^2 .

It is a cyclic number.

It is not a de Polignac number, because 208918906549 - 2³ = 208918906541 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208918906541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104459453274 + 104459453275.

It is an arithmetic number, because the mean of its divisors is an integer number (104459453275).

Almost surely, 2^208918906549 is an apocalyptic number.

It is an amenable number.

208918906549 is a deficient number, since it is larger than the sum of its proper divisors (1).

208918906549 is an equidigital number, since it uses as much as digits as its factorization.

208918906549 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11197440, while the sum is 61.

The spelling of 208918906549 in words is "two hundred eight billion, nine hundred eighteen million, nine hundred six thousand, five hundred forty-nine".