208840609 has 4 divisors (see below), whose sum is σ = 219832240. Its totient is φ = 197848980.

The previous prime is 208840591. The next prime is 208840627. The reversal of 208840609 is 906048802.

208840609 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 an interprime number because it is at equal distance from previous prime (208840591) and next prime (208840627).

It is a cyclic number.

It is not a de Polignac number, because 208840609 - 2⁷ = 208840481 is a prime.

It is a super-2 number, since 2×208840609² = 87228799934981762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208840669) 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, 5495787 + ... + 5495824.

It is an arithmetic number, because the mean of its divisors is an integer number (54958060).

Almost surely, 2^208840609 is an apocalyptic number.

It is an amenable number.

208840609 is a deficient number, since it is larger than the sum of its proper divisors (10991631).

208840609 is a wasteful number, since it uses less digits than its factorization.

208840609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10991630.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 208840609 is about 14451.3185903571. The cubic root of 208840609 is about 593.2963141978.

The spelling of 208840609 in words is "two hundred eight million, eight hundred forty thousand, six hundred nine".