199938409 has 4 divisors (see below), whose sum is σ = 218114640. Its totient is φ = 181762180.

The previous prime is 199938407. The next prime is 199938421. The reversal of 199938409 is 904839991.

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 199938409 - 2¹ = 199938407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (199938407) 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, 9088099 + ... + 9088120.

It is an arithmetic number, because the mean of its divisors is an integer number (54528660).

Almost surely, 2^199938409 is an apocalyptic number.

It is an amenable number.

199938409 is a deficient number, since it is larger than the sum of its proper divisors (18176231).

199938409 is a wasteful number, since it uses less digits than its factorization.

199938409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18176230.

The product of its (nonzero) digits is 629856, while the sum is 52.

The square root of 199938409 is about 14139.9578853687. The cubic root of 199938409 is about 584.7435104204.

The spelling of 199938409 in words is "one hundred ninety-nine million, nine hundred thirty-eight thousand, four hundred nine".