208289639 has 2 divisors, whose sum is σ = 208289640. Its totient is φ = 208289638.

The previous prime is 208289621. The next prime is 208289657. The reversal of 208289639 is 936982802.

It is a balanced prime because it is at equal distance from previous prime (208289621) and next prime (208289657).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-208289639 is a prime.

It is a Sophie Germain prime.

It is a plaindrome in base 15.

It is a junction number, because it is equal to n+sod(n) for n = 208289593 and 208289602.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208289689) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104144819 + 104144820.

It is an arithmetic number, because the mean of its divisors is an integer number (104144820).

Almost surely, 2^208289639 is an apocalyptic number.

208289639 is a deficient number, since it is larger than the sum of its proper divisors (1).

208289639 is an equidigital number, since it uses as much as digits as its factorization.

208289639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 373248, while the sum is 47.

The square root of 208289639 is about 14432.2430342619. The cubic root of 208289639 is about 592.7741035621.

The spelling of 208289639 in words is "two hundred eight million, two hundred eighty-nine thousand, six hundred thirty-nine".