208148009 has 4 divisors (see below), whose sum is σ = 209298180. Its totient is φ = 206997840.

The previous prime is 208147997. The next prime is 208148011. The reversal of 208148009 is 900841802.

It is a happy number.

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 81090025 + 127057984 = 9005^2 + 11272^2 .

It is a cyclic number.

It is not a de Polignac number, because 208148009 - 2¹² = 208143913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (208148099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 574814 + ... + 575175.

It is an arithmetic number, because the mean of its divisors is an integer number (52324545).

Almost surely, 2^208148009 is an apocalyptic number.

It is an amenable number.

208148009 is a deficient number, since it is larger than the sum of its proper divisors (1150171).

208148009 is a wasteful number, since it uses less digits than its factorization.

208148009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1150170.

The product of its (nonzero) digits is 4608, while the sum is 32.

The square root of 208148009 is about 14427.3354781817. The cubic root of 208148009 is about 592.6397175654.

The spelling of 208148009 in words is "two hundred eight million, one hundred forty-eight thousand, nine".