199999917 has 48 divisors (see below), whose sum is σ = 331753968. Its totient is φ = 115015680.

The previous prime is 199999903. The next prime is 199999931. The reversal of 199999917 is 719999991.

It is an interprime number because it is at equal distance from previous prime (199999903) and next prime (199999931).

It can be written as a sum of positive squares in 8 ways, for example, as 16695396 + 183304521 = 4086^2 + 13539^2 .

It is not a de Polignac number, because 199999917 - 2⁴ = 199999901 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199999957) 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 in 47 ways as a sum of consecutive naturals, for example, 383617 + ... + 384137.

It is an arithmetic number, because the mean of its divisors is an integer number (6911541).

Almost surely, 2^199999917 is an apocalyptic number.

199999917 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

199999917 is a deficient number, since it is larger than the sum of its proper divisors (131754051).

199999917 is a wasteful number, since it uses less digits than its factorization.

199999917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 750 (or 747 counting only the distinct ones).

The product of its digits is 3720087, while the sum is 63.

The square root of 199999917 is about 14142.1326892375. The cubic root of 199999917 is about 584.8034667447.

The spelling of 199999917 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred seventeen".