999957509 has 2 divisors, whose sum is σ = 999957510. Its totient is φ = 999957508.

The previous prime is 999957503. The next prime is 999957529. The reversal of 999957509 is 905759999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 875568100 + 124389409 = 29590^2 + 11153^2 .

It is an emirp because it is prime and its reverse (905759999) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 999957509 - 2⁸ = 999957253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999957503) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499978754 + 499978755.

It is an arithmetic number, because the mean of its divisors is an integer number (499978755).

Almost surely, 2^999957509 is an apocalyptic number.

It is an amenable number.

999957509 is a deficient number, since it is larger than the sum of its proper divisors (1).

999957509 is an equidigital number, since it uses as much as digits as its factorization.

999957509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10333575, while the sum is 62.

The square root of 999957509 is about 31622.1047528465. The cubic root of 999957509 is about 999.9858361327.

The spelling of 999957509 in words is "nine hundred ninety-nine million, nine hundred fifty-seven thousand, five hundred nine".