208807813 has 8 divisors (see below), whose sum is σ = 211942808. Its totient is φ = 205680384.

The previous prime is 208807799. The next prime is 208807817. The reversal of 208807813 is 318708802.

It can be written as a sum of positive squares in 4 ways, for example, as 161239204 + 47568609 = 12698^2 + 6897^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 208807813 - 2²⁵ = 175253381 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 (208807817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 78481 + ... + 81097.

It is an arithmetic number, because the mean of its divisors is an integer number (26492851).

Almost surely, 2^208807813 is an apocalyptic number.

It is an amenable number.

208807813 is a deficient number, since it is larger than the sum of its proper divisors (3134995).

208807813 is a wasteful number, since it uses less digits than its factorization.

208807813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3783.

The product of its (nonzero) digits is 21504, while the sum is 37.

The square root of 208807813 is about 14450.1838396610. The cubic root of 208807813 is about 593.2652557994.

The spelling of 208807813 in words is "two hundred eight million, eight hundred seven thousand, eight hundred thirteen".