999999000001 has 2 divisors, whose sum is σ = 999999000002.
Its totient is φ = 999999000000.
The previous prime is 999998999999. The next prime is 999999000053. The reversal of 999999000001 is 100000999999.
It is a happy number.
999999000001 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 999998000001 + 1000000 = 999999^2 + 1000^2
It is a cyclic number.
It is not a de Polignac number, because 999999000001 - 21 = 999998999999 is a prime.
Together with 999998999999, it forms a pair of twin primes.
It is the 1000000-th Hogben number.
It is a junction number, because it is equal to n+sod(n) for n = 999998999897 and 999998999906.
It is not a weakly prime, because it can be changed into another prime (999999060001) by changing a digit.
It is a nontrivial repunit in base 999999.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499999500000 + 499999500001.
It is an arithmetic number, because the mean of its divisors is an integer number (499999500001).
Almost surely, 2999999000001 is an apocalyptic number.
It is an amenable number.
999999000001 is a deficient number, since it is larger than the sum of its proper divisors (1).
999999000001 is an equidigital number, since it uses as much as digits as its factorization.
999999000001 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 531441, while the sum is 55.
The spelling of 999999000001 in words is "nine hundred ninety-nine billion, nine hundred ninety-nine million, one", and thus it is an aban number.