199813919 has 4 divisors (see below), whose sum is σ = 199942680. Its totient is φ = 199685160.

The previous prime is 199813909. The next prime is 199813927. The reversal of 199813919 is 919318991.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 199813919 - 2¹⁶ = 199748383 is a prime.

It is a super-2 number, since 2×199813919² = 79851204452277122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199813909) 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, 62024 + ... + 65165.

It is an arithmetic number, because the mean of its divisors is an integer number (49985670).

Almost surely, 2^199813919 is an apocalyptic number.

199813919 is a deficient number, since it is larger than the sum of its proper divisors (128761).

199813919 is a wasteful number, since it uses less digits than its factorization.

199813919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128760.

The product of its digits is 157464, while the sum is 50.

The square root of 199813919 is about 14135.5551358976. Note that the first 3 decimals coincide. The cubic root of 199813919 is about 584.6221233167.

The spelling of 199813919 in words is "one hundred ninety-nine million, eight hundred thirteen thousand, nine hundred nineteen".