99999865 has 16 divisors (see below), whose sum is σ = 145210752.
Its totient is φ = 64537344.
The previous prime is 99999847. The next prime is 99999931. The reversal of 99999865 is 56899999.
It is a cyclic number.
It is not a de Polignac number, because 99999865 - 29 = 99999353 is a prime.
It is a Duffinian number.
It is a nialpdrome in base 10.
It is a junction number, because it is equal to n+sod(n) for n = 99999797 and 99999806.
It is an unprimeable number.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83439 + ... + 84628.
It is an arithmetic number, because the mean of its divisors is an integer number (9075672).
Almost surely, 299999865 is an apocalyptic number.
It is an amenable number.
99999865 is a deficient number, since it is larger than the sum of its proper divisors (45210887).
99999865 is a wasteful number, since it uses less digits than its factorization.
99999865 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 168096.
The product of its digits is 14171760, while the sum is 64.
The square root of 99999865 is about 9999.9932499977.
The cubic root of 99999865 is about 464.1586744897.
The spelling of 99999865 in words is "ninety-nine million, nine hundred ninety-nine thousand, eight hundred sixty-five".