199290409 has 4 divisors (see below), whose sum is σ = 199390660. Its totient is φ = 199190160.

The previous prime is 199290391. The next prime is 199290437. The reversal of 199290409 is 904092991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 904092991 = 3167 ⋅285473.

It can be written as a sum of positive squares in 2 ways, for example, as 118200384 + 81090025 = 10872^2 + 9005^2 .

It is a cyclic number.

It is not a de Polignac number, because 199290409 - 2⁷ = 199290281 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199290499) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47082 + ... + 51139.

It is an arithmetic number, because the mean of its divisors is an integer number (49847665).

Almost surely, 2^199290409 is an apocalyptic number.

It is an amenable number.

199290409 is a deficient number, since it is larger than the sum of its proper divisors (100251).

199290409 is an equidigital number, since it uses as much as digits as its factorization.

199290409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100250.

The product of its (nonzero) digits is 52488, while the sum is 43.

The square root of 199290409 is about 14117.0255011458. The cubic root of 199290409 is about 584.1111091920. Note that the first 4 decimals are identical.

The spelling of 199290409 in words is "one hundred ninety-nine million, two hundred ninety thousand, four hundred nine".