999001999 has 2 divisors, whose sum is σ = 999002000. Its totient is φ = 999001998.

The previous prime is 999001943. The next prime is 999002051. The reversal of 999001999 is 999100999.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 999001999 - 2¹⁷ = 998870927 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999001099) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499500999 + 499501000.

It is an arithmetic number, because the mean of its divisors is an integer number (499501000).

Almost surely, 2^999001999 is an apocalyptic number.

999001999 is a deficient number, since it is larger than the sum of its proper divisors (1).

999001999 is an equidigital number, since it uses as much as digits as its factorization.

999001999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 531441, while the sum is 55.

The square root of 999001999 is about 31606.9928813230. The cubic root of 999001999 is about 999.6672222713.

It can be divided in two parts, 999001 and 999, that added together give a 6-th power (1000000 = 10⁶).

The spelling of 999001999 in words is "nine hundred ninety-nine million, one thousand, nine hundred ninety-nine".