206391857801 has 2 divisors, whose sum is σ = 206391857802. Its totient is φ = 206391857800.

The previous prime is 206391857773. The next prime is 206391857827. The reversal of 206391857801 is 108758193602.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 197900419600 + 8491438201 = 444860^2 + 92149^2 .

It is a cyclic number.

It is not a de Polignac number, because 206391857801 - 2¹⁴ = 206391841417 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 206391857801.

It is not a weakly prime, because it can be changed into another prime (206391857831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 103195928900 + 103195928901.

It is an arithmetic number, because the mean of its divisors is an integer number (103195928901).

Almost surely, 2^206391857801 is an apocalyptic number.

It is an amenable number.

206391857801 is a deficient number, since it is larger than the sum of its proper divisors (1).

206391857801 is an equidigital number, since it uses as much as digits as its factorization.

206391857801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 206391857801 in words is "two hundred six billion, three hundred ninety-one million, eight hundred fifty-seven thousand, eight hundred one".