209009779829 has 2 divisors, whose sum is σ = 209009779830. Its totient is φ = 209009779828.

The previous prime is 209009779817. The next prime is 209009779873. The reversal of 209009779829 is 928977900902.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 203241377329 + 5768402500 = 450823^2 + 75950^2 .

It is a cyclic number.

It is not a de Polignac number, because 209009779829 - 2¹⁶ = 209009714293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (209009749829) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104504889914 + 104504889915.

It is an arithmetic number, because the mean of its divisors is an integer number (104504889915).

Almost surely, 2^209009779829 is an apocalyptic number.

It is an amenable number.

209009779829 is a deficient number, since it is larger than the sum of its proper divisors (1).

209009779829 is an equidigital number, since it uses as much as digits as its factorization.

209009779829 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10287648, while the sum is 62.

The spelling of 209009779829 in words is "two hundred nine billion, nine million, seven hundred seventy-nine thousand, eight hundred twenty-nine".