784409 has 2 divisors, whose sum is σ = 784410. Its totient is φ = 784408.

The previous prime is 784387. The next prime is 784411. The reversal of 784409 is 904487.

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., 760384 + 24025 = 872^2 + 155^2 .

It is a cyclic number.

It is not a de Polignac number, because 784409 - 2⁸ = 784153 is a prime.

Together with 784411, 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 (784489) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 392204 + 392205.

It is an arithmetic number, because the mean of its divisors is an integer number (392205).

2⁷⁸⁴⁴⁰⁹ is an apocalyptic number.

It is an amenable number.

784409 is a deficient number, since it is larger than the sum of its proper divisors (1).

784409 is an equidigital number, since it uses as much as digits as its factorization.

784409 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 784409 is about 885.6686739408. The cubic root of 784409 is about 92.2247576493.

The spelling of 784409 in words is "seven hundred eighty-four thousand, four hundred nine".