209908939 has 2 divisors, whose sum is σ = 209908940. Its totient is φ = 209908938.

The previous prime is 209908927. The next prime is 209908969. The reversal of 209908939 is 939809902.

209908939 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209908939 - 2¹¹ = 209906891 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 209908892 and 209908901.

It is not a weakly prime, because it can be changed into another prime (209908969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104954469 + 104954470.

It is an arithmetic number, because the mean of its divisors is an integer number (104954470).

Almost surely, 2^209908939 is an apocalyptic number.

209908939 is a deficient number, since it is larger than the sum of its proper divisors (1).

209908939 is an equidigital number, since it uses as much as digits as its factorization.

209908939 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 314928, while the sum is 49.

The square root of 209908939 is about 14488.2345025196. The cubic root of 209908939 is about 594.3062686525.

It can be divided in two parts, 20990 and 8939, that added together give a square (29929 = 173²).

The spelling of 209908939 in words is "two hundred nine million, nine hundred eight thousand, nine hundred thirty-nine".