9999919 has 4 divisors (see below), whose sum is σ = 10057896.
Its totient is φ = 9941944.
The previous prime is 9999907. The next prime is 9999929. The reversal of 9999919 is 9199999.
It is a happy number.
9999919 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9199999 = 131 ⋅70229.
It is a cyclic number.
It is not a de Polignac number, because 9999919 - 213 = 9991727 is a prime.
It is a super-2 number, since 2×99999192 = 199996760013122, which contains 22 as substring.
It is a Duffinian number.
It is a self number, because there is not a number n which added to its sum of digits gives 9999919.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (9999929) 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, 28729 + ... + 29074.
It is an arithmetic number, because the mean of its divisors is an integer number (2514474).
Almost surely, 29999919 is an apocalyptic number.
9999919 is a deficient number, since it is larger than the sum of its proper divisors (57977).
9999919 is a wasteful number, since it uses less digits than its factorization.
9999919 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 57976.
The product of its digits is 531441, while the sum is 55.
The square root of 9999919 is about 3162.2648529179.
The cubic root of 9999919 is about 215.4428873043.
The spelling of 9999919 in words is "nine million, nine hundred ninety-nine thousand, nine hundred nineteen".