208639065 has 16 divisors (see below), whose sum is σ = 334285056. Its totient is φ = 111120000.

The previous prime is 208639061. The next prime is 208639073. The reversal of 208639065 is 560936802.

It is not a de Polignac number, because 208639065 - 2² = 208639061 is a prime.

It is not an unprimeable number, because it can be changed into a prime (208639061) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2005 + ... + 20525.

It is an arithmetic number, because the mean of its divisors is an integer number (20892816).

Almost surely, 2^208639065 is an apocalyptic number.

It is an amenable number.

208639065 is a deficient number, since it is larger than the sum of its proper divisors (125645991).

208639065 is a wasteful number, since it uses less digits than its factorization.

208639065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19280.

The product of its (nonzero) digits is 77760, while the sum is 39.

The square root of 208639065 is about 14444.3437026401. The cubic root of 208639065 is about 593.1053969884.

The spelling of 208639065 in words is "two hundred eight million, six hundred thirty-nine thousand, sixty-five".