198635813 has 2 divisors, whose sum is σ = 198635814. Its totient is φ = 198635812.

The previous prime is 198635743. The next prime is 198635821. The reversal of 198635813 is 318536891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 188183524 + 10452289 = 13718^2 + 3233^2 .

It is an emirp because it is prime and its reverse (318536891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198635813 - 2²² = 194441509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198635863) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99317906 + 99317907.

It is an arithmetic number, because the mean of its divisors is an integer number (99317907).

Almost surely, 2^198635813 is an apocalyptic number.

It is an amenable number.

198635813 is a deficient number, since it is larger than the sum of its proper divisors (1).

198635813 is an equidigital number, since it uses as much as digits as its factorization.

198635813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 44.

The square root of 198635813 is about 14093.8218024779. The cubic root of 198635813 is about 583.4708773528.

The spelling of 198635813 in words is "one hundred ninety-eight million, six hundred thirty-five thousand, eight hundred thirteen".