99942509 has 2 divisors, whose sum is σ = 99942510. Its totient is φ = 99942508.

The previous prime is 99942503. The next prime is 99942533. The reversal of 99942509 is 90524999.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99940009 + 2500 = 9997^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 99942509 - 2⁸ = 99942253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (99942503) 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, 49971254 + 49971255.

It is an arithmetic number, because the mean of its divisors is an integer number (49971255).

Almost surely, 2^99942509 is an apocalyptic number.

It is an amenable number.

99942509 is a deficient number, since it is larger than the sum of its proper divisors (1).

99942509 is an equidigital number, since it uses as much as digits as its factorization.

99942509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 262440, while the sum is 47.

The square root of 99942509 is about 9997.1250367293. The cubic root of 99942509 is about 464.0699164486.

The spelling of 99942509 in words is "ninety-nine million, nine hundred forty-two thousand, five hundred nine".