208198136173 has 2 divisors, whose sum is σ = 208198136174. Its totient is φ = 208198136172.

The previous prime is 208198136143. The next prime is 208198136197. The reversal of 208198136173 is 371631891802.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 183606251049 + 24591885124 = 428493^2 + 156818^2 .

It is a cyclic number.

It is not a de Polignac number, because 208198136173 - 2¹⁷ = 208198005101 is a prime.

It is a super-2 number, since 2×208198136173² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (208198136143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 104099068086 + 104099068087.

It is an arithmetic number, because the mean of its divisors is an integer number (104099068087).

Almost surely, 2^208198136173 is an apocalyptic number.

It is an amenable number.

208198136173 is a deficient number, since it is larger than the sum of its proper divisors (1).

208198136173 is an equidigital number, since it uses as much as digits as its factorization.

208198136173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 435456, while the sum is 49.

The spelling of 208198136173 in words is "two hundred eight billion, one hundred ninety-eight million, one hundred thirty-six thousand, one hundred seventy-three".