209848139 has 2 divisors, whose sum is σ = 209848140. Its totient is φ = 209848138.

The previous prime is 209848123. The next prime is 209848157. The reversal of 209848139 is 931848902.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 209848139 - 2⁴ = 209848123 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 209848139.

It is not a weakly prime, because it can be changed into another prime (209848169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104924069 + 104924070.

It is an arithmetic number, because the mean of its divisors is an integer number (104924070).

Almost surely, 2^209848139 is an apocalyptic number.

209848139 is a deficient number, since it is larger than the sum of its proper divisors (1).

209848139 is an equidigital number, since it uses as much as digits as its factorization.

209848139 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 209848139 is about 14486.1360962819. The cubic root of 209848139 is about 594.2488829585.

The spelling of 209848139 in words is "two hundred nine million, eight hundred forty-eight thousand, one hundred thirty-nine".