209281339 has 4 divisors (see below), whose sum is σ = 221592024. Its totient is φ = 196970656.

The previous prime is 209281321. The next prime is 209281351. The reversal of 209281339 is 933182902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 933182902 = 2 ⋅466591451.

It is a cyclic number.

It is not a de Polignac number, because 209281339 - 2⁷ = 209281211 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 209281298 and 209281307.

It is not an unprimeable number, because it can be changed into a prime (209281379) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6155317 + ... + 6155350.

It is an arithmetic number, because the mean of its divisors is an integer number (55398006).

Almost surely, 2^209281339 is an apocalyptic number.

209281339 is a deficient number, since it is larger than the sum of its proper divisors (12310685).

209281339 is a wasteful number, since it uses less digits than its factorization.

209281339 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12310684.

The product of its (nonzero) digits is 23328, while the sum is 37.

The square root of 209281339 is about 14466.5593352393. The cubic root of 209281339 is about 593.7133782916.

The spelling of 209281339 in words is "two hundred nine million, two hundred eighty-one thousand, three hundred thirty-nine".