102409 has 2 divisors, whose sum is σ = 102410. Its totient is φ = 102408.

The previous prime is 102407. The next prime is 102433. The reversal of 102409 is 904201.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102400 + 9 = 320^2 + 3^2 .

It is an emirp because it is prime and its reverse (904201) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 102409 - 2¹ = 102407 is a prime.

Together with 102407, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 102392 and 102401.

It is not a weakly prime, because it can be changed into another prime (102407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51204 + 51205.

It is an arithmetic number, because the mean of its divisors is an integer number (51205).

2¹⁰²⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

102409 is a deficient number, since it is larger than the sum of its proper divisors (1).

102409 is an equidigital number, since it uses as much as digits as its factorization.

102409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 102409 is about 320.0140621910. The cubic root of 102409 is about 46.7856544046.

It can be divided in two parts, 10 and 2409, that multiplied together give a triangular number (24090 = T₂₁₉).

The spelling of 102409 in words is "one hundred two thousand, four hundred nine".