199636813 has 2 divisors, whose sum is σ = 199636814. Its totient is φ = 199636812.

The previous prime is 199636799. The next prime is 199636847. The reversal of 199636813 is 318636991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111239209 + 88397604 = 10547^2 + 9402^2 .

It is a cyclic number.

It is not a de Polignac number, because 199636813 - 2⁹ = 199636301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199636873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99818406 + 99818407.

It is an arithmetic number, because the mean of its divisors is an integer number (99818407).

Almost surely, 2^199636813 is an apocalyptic number.

It is an amenable number.

199636813 is a deficient number, since it is larger than the sum of its proper divisors (1).

199636813 is an equidigital number, since it uses as much as digits as its factorization.

199636813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 209952, while the sum is 46.

The square root of 199636813 is about 14129.2891894815. The cubic root of 199636813 is about 584.4493447427.

It can be divided in two parts, 1996 and 36813, that added together give a square (38809 = 197²).

The spelling of 199636813 in words is "one hundred ninety-nine million, six hundred thirty-six thousand, eight hundred thirteen".