99409 has 2 divisors, whose sum is σ = 99410. Its totient is φ = 99408.

The previous prime is 99401. The next prime is 99431. The reversal of 99409 is 90499.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90000 + 9409 = 300^2 + 97^2 .

It is an emirp because it is prime and its reverse (90499) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 99409 - 2³ = 99401 is a prime.

It is not a weakly prime, because it can be changed into another prime (99401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 49704 + 49705.

It is an arithmetic number, because the mean of its divisors is an integer number (49705).

2⁹⁹⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

99409 is a deficient number, since it is larger than the sum of its proper divisors (1).

99409 is an equidigital number, since it uses as much as digits as its factorization.

99409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 99409 is about 315.2919282189. The cubic root of 99409 is about 46.3242683069.

It can be divided in two parts, 9 and 9409, that multiplied together give a square (84681 = 291²).

The spelling of 99409 in words is "ninety-nine thousand, four hundred nine".