199999997 has 4 divisors (see below), whose sum is σ = 200269920. Its totient is φ = 199730076.

The previous prime is 199999991. The next prime is 200000033. The reversal of 199999997 is 799999991.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 199999997 - 2¹⁴ = 199983613 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 199999997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199999991) 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 in 3 ways as a sum of consecutive naturals, for example, 133847 + ... + 135332.

It is an arithmetic number, because the mean of its divisors is an integer number (50067480).

Almost surely, 2^199999997 is an apocalyptic number.

It is an amenable number.

199999997 is a deficient number, since it is larger than the sum of its proper divisors (269923).

199999997 is an equidigital number, since it uses as much as digits as its factorization.

199999997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 269922.

The product of its digits is 33480783, while the sum is 71.

The square root of 199999997 is about 14142.1355176649. The cubic root of 199999997 is about 584.8035447186.

The spelling of 199999997 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred ninety-seven".