199718641 has 2 divisors, whose sum is σ = 199718642. Its totient is φ = 199718640.

The previous prime is 199718627. The next prime is 199718657. The reversal of 199718641 is 146817991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 199628641 + 90000 = 14129^2 + 300^2 .

It is a cyclic number.

It is not a de Polignac number, because 199718641 - 2⁵ = 199718609 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 199718591 and 199718600.

It is not a weakly prime, because it can be changed into another prime (199712641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99859320 + 99859321.

It is an arithmetic number, because the mean of its divisors is an integer number (99859321).

Almost surely, 2^199718641 is an apocalyptic number.

It is an amenable number.

199718641 is a deficient number, since it is larger than the sum of its proper divisors (1).

199718641 is an equidigital number, since it uses as much as digits as its factorization.

199718641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 46.

The square root of 199718641 is about 14132.1845798871. The cubic root of 199718641 is about 584.5291860432.

The spelling of 199718641 in words is "one hundred ninety-nine million, seven hundred eighteen thousand, six hundred forty-one".