199999965 has 16 divisors (see below), whose sum is σ = 349091136.
Its totient is φ = 96969600.
The previous prime is 199999963. The next prime is 199999991. The reversal of 199999965 is 569999991.
It is not a de Polignac number, because 199999965 - 21 = 199999963 is a prime.
It is a Curzon number.
It is a junction number, because it is equal to n+sod(n) for n = 199999896 and 199999905.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (199999963) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 605896 + ... + 606225.
It is an arithmetic number, because the mean of its divisors is an integer number (21818196).
Almost surely, 2199999965 is an apocalyptic number.
199999965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.
It is an amenable number.
199999965 is a deficient number, since it is larger than the sum of its proper divisors (149091171).
199999965 is a wasteful number, since it uses less digits than its factorization.
199999965 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 1212140.
The product of its digits is 15943230, while the sum is 66.
The square root of 199999965 is about 14142.1343862940.
The cubic root of 199999965 is about 584.8035135290.
The spelling of 199999965 in words is "one hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred sixty-five".