99855409 has 2 divisors, whose sum is σ = 99855410. Its totient is φ = 99855408.

The previous prime is 99855407. The next prime is 99855421. The reversal of 99855409 is 90455899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 97614400 + 2241009 = 9880^2 + 1497^2 .

It is a cyclic number.

It is not a de Polignac number, because 99855409 - 2¹ = 99855407 is a prime.

It is a super-2 number, since 2×99855409² = 19942205413114562, which contains 22 as substring.

Together with 99855407, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (99855403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49927704 + 49927705.

It is an arithmetic number, because the mean of its divisors is an integer number (49927705).

Almost surely, 2^99855409 is an apocalyptic number.

It is an amenable number.

99855409 is a deficient number, since it is larger than the sum of its proper divisors (1).

99855409 is an equidigital number, since it uses as much as digits as its factorization.

99855409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 583200, while the sum is 49.

The square root of 99855409 is about 9992.7678347893. The cubic root of 99855409 is about 463.9350647957.

The spelling of 99855409 in words is "ninety-nine million, eight hundred fifty-five thousand, four hundred nine".