99902809 has 2 divisors, whose sum is σ = 99902810. Its totient is φ = 99902808.

The previous prime is 99902771. The next prime is 99902813. The reversal of 99902809 is 90820999.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55547209 + 44355600 = 7453^2 + 6660^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-99902809 is a prime.

It is not a weakly prime, because it can be changed into another prime (99903809) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49951404 + 49951405.

It is an arithmetic number, because the mean of its divisors is an integer number (49951405).

Almost surely, 2^99902809 is an apocalyptic number.

It is an amenable number.

99902809 is a deficient number, since it is larger than the sum of its proper divisors (1).

99902809 is an equidigital number, since it uses as much as digits as its factorization.

99902809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 46.

The square root of 99902809 is about 9995.1392686645. The cubic root of 99902809 is about 464.0084610650.

The spelling of 99902809 in words is "ninety-nine million, nine hundred two thousand, eight hundred nine".