208521544897 has 2 divisors, whose sum is σ = 208521544898. Its totient is φ = 208521544896.

The previous prime is 208521544883. The next prime is 208521544909. The reversal of 208521544897 is 798445125802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 207470229121 + 1051315776 = 455489^2 + 32424^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208521544897 is a prime.

It is not a weakly prime, because it can be changed into another prime (208521544807) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104260772448 + 104260772449.

It is an arithmetic number, because the mean of its divisors is an integer number (104260772449).

Almost surely, 2^208521544897 is an apocalyptic number.

It is an amenable number.

208521544897 is a deficient number, since it is larger than the sum of its proper divisors (1).

208521544897 is an equidigital number, since it uses as much as digits as its factorization.

208521544897 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6451200, while the sum is 55.

The spelling of 208521544897 in words is "two hundred eight billion, five hundred twenty-one million, five hundred forty-four thousand, eight hundred ninety-seven".