684486409 has 2 divisors, whose sum is σ = 684486410. Its totient is φ = 684486408.

The previous prime is 684486401. The next prime is 684486503. The reversal of 684486409 is 904684486.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 659205625 + 25280784 = 25675^2 + 5028^2 .

It is a cyclic number.

It is not a de Polignac number, because 684486409 - 2³ = 684486401 is a prime.

It is not a weakly prime, because it can be changed into another prime (684486401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342243204 + 342243205.

It is an arithmetic number, because the mean of its divisors is an integer number (342243205).

Almost surely, 2^684486409 is an apocalyptic number.

It is an amenable number.

684486409 is a deficient number, since it is larger than the sum of its proper divisors (1).

684486409 is an equidigital number, since it uses as much as digits as its factorization.

684486409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1327104, while the sum is 49.

The square root of 684486409 is about 26162.6911650923. The cubic root of 684486409 is about 881.2956160751.

The spelling of 684486409 in words is "six hundred eighty-four million, four hundred eighty-six thousand, four hundred nine".