209009779387 has 2 divisors, whose sum is σ = 209009779388. Its totient is φ = 209009779386.

The previous prime is 209009779337. The next prime is 209009779397. The reversal of 209009779387 is 783977900902.

209009779387 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 is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-209009779387 is a prime.

It is not a weakly prime, because it can be changed into another prime (209009779337) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104504889693 + 104504889694.

It is an arithmetic number, because the mean of its divisors is an integer number (104504889694).

Almost surely, 2^209009779387 is an apocalyptic number.

209009779387 is a deficient number, since it is larger than the sum of its proper divisors (1).

209009779387 is an equidigital number, since it uses as much as digits as its factorization.

209009779387 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12002256, while the sum is 61.

The spelling of 209009779387 in words is "two hundred nine billion, nine million, seven hundred seventy-nine thousand, three hundred eighty-seven".