208117768213 has 4 divisors (see below), whose sum is σ = 208270684908. Its totient is φ = 207964851520.

The previous prime is 208117768153. The next prime is 208117768223. The reversal of 208117768213 is 312867711802.

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 75826984689 + 132290783524 = 275367^2 + 363718^2 .

It is a cyclic number.

It is not a de Polignac number, because 208117768213 - 2²⁹ = 207580897301 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 (208117768223) 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, 76456306 + ... + 76459027.

It is an arithmetic number, because the mean of its divisors is an integer number (52067671227).

Almost surely, 2^208117768213 is an apocalyptic number.

It is an amenable number.

208117768213 is a deficient number, since it is larger than the sum of its proper divisors (152916695).

208117768213 is a wasteful number, since it uses less digits than its factorization.

208117768213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152916694.

The product of its (nonzero) digits is 225792, while the sum is 46.

The spelling of 208117768213 in words is "two hundred eight billion, one hundred seventeen million, seven hundred sixty-eight thousand, two hundred thirteen".