208117794431 has 2 divisors, whose sum is σ = 208117794432. Its totient is φ = 208117794430.

The previous prime is 208117794421. The next prime is 208117794491. The reversal of 208117794431 is 134497711802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 208117794431 - 2²² = 208113600127 is a prime.

It is a super-2 number, since 2×208117794431² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208117794421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104058897215 + 104058897216.

It is an arithmetic number, because the mean of its divisors is an integer number (104058897216).

Almost surely, 2^208117794431 is an apocalyptic number.

208117794431 is a deficient number, since it is larger than the sum of its proper divisors (1).

208117794431 is an equidigital number, since it uses as much as digits as its factorization.

208117794431 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 338688, while the sum is 47.

The spelling of 208117794431 in words is "two hundred eight billion, one hundred seventeen million, seven hundred ninety-four thousand, four hundred thirty-one".