208749109 has 4 divisors (see below), whose sum is σ = 209420640. Its totient is φ = 208077580.

The previous prime is 208749091. The next prime is 208749113. The reversal of 208749109 is 901947802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 208749109 - 2⁹ = 208748597 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 (208749169) 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, 335299 + ... + 335920.

It is an arithmetic number, because the mean of its divisors is an integer number (52355160).

Almost surely, 2^208749109 is an apocalyptic number.

It is an amenable number.

208749109 is a deficient number, since it is larger than the sum of its proper divisors (671531).

208749109 is an equidigital number, since it uses as much as digits as its factorization.

208749109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 671530.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 208749109 is about 14448.1524424405. The cubic root of 208749109 is about 593.2096539402.

The spelling of 208749109 in words is "two hundred eight million, seven hundred forty-nine thousand, one hundred nine".