999938005909 has 2 divisors, whose sum is σ = 999938005910. Its totient is φ = 999938005908.

The previous prime is 999938005901. The next prime is 999938005939. The reversal of 999938005909 is 909500839999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 998606485809 + 1331520100 = 999303^2 + 36490^2 .

It is a cyclic number.

It is not a de Polignac number, because 999938005909 - 2³ = 999938005901 is a prime.

It is a super-2 number, since 2×999938005909² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999938005901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499969002954 + 499969002955.

It is an arithmetic number, because the mean of its divisors is an integer number (499969002955).

Almost surely, 2^999938005909 is an apocalyptic number.

It is an amenable number.

999938005909 is a deficient number, since it is larger than the sum of its proper divisors (1).

999938005909 is an equidigital number, since it uses as much as digits as its factorization.

999938005909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 63772920, while the sum is 70.

The spelling of 999938005909 in words is "nine hundred ninety-nine billion, nine hundred thirty-eight million, five thousand, nine hundred nine".