208236109 has 4 divisors (see below), whose sum is σ = 208289116. Its totient is φ = 208183104.

The previous prime is 208236103. The next prime is 208236139. The reversal of 208236109 is 901632802.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 105781225 + 102454884 = 10285^2 + 10122^2 .

It is a cyclic number.

It is not a de Polignac number, because 208236109 - 2²⁵ = 174681677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208236103) 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, 20094 + ... + 28639.

It is an arithmetic number, because the mean of its divisors is an integer number (52072279).

Almost surely, 2^208236109 is an apocalyptic number.

It is an amenable number.

208236109 is a deficient number, since it is larger than the sum of its proper divisors (53007).

208236109 is an equidigital number, since it uses as much as digits as its factorization.

208236109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53006.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 208236109 is about 14430.3883870116. The cubic root of 208236109 is about 592.7233186446.

The spelling of 208236109 in words is "two hundred eight million, two hundred thirty-six thousand, one hundred nine".