199999013 has 4 divisors (see below), whose sum is σ = 200065068. Its totient is φ = 199932960.

The previous prime is 199999001. The next prime is 199999043. The reversal of 199999013 is 310999991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 310999991 = 7927 ⋅39233.

It can be written as a sum of positive squares in 2 ways, for example, as 98049604 + 101949409 = 9902^2 + 10097^2 .

It is a cyclic number.

It is not a de Polignac number, because 199999013 - 2¹⁰ = 199997989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199999043) 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, 28256 + ... + 34617.

It is an arithmetic number, because the mean of its divisors is an integer number (50016267).

Almost surely, 2^199999013 is an apocalyptic number.

It is an amenable number.

199999013 is a deficient number, since it is larger than the sum of its proper divisors (66055).

199999013 is an equidigital number, since it uses as much as digits as its factorization.

199999013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66054.

The product of its (nonzero) digits is 177147, while the sum is 50.

The square root of 199999013 is about 14142.1007279682. The cubic root of 199999013 is about 584.8025856392.

The spelling of 199999013 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, thirteen".