684340999 has 2 divisors, whose sum is σ = 684341000. Its totient is φ = 684340998.

The previous prime is 684340997. The next prime is 684341017. The reversal of 684340999 is 999043486.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684340999 - 2¹ = 684340997 is a prime.

Together with 684340997, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684340997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342170499 + 342170500.

It is an arithmetic number, because the mean of its divisors is an integer number (342170500).

Almost surely, 2^684340999 is an apocalyptic number.

684340999 is a deficient number, since it is larger than the sum of its proper divisors (1).

684340999 is an equidigital number, since it uses as much as digits as its factorization.

684340999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1679616, while the sum is 52.

The square root of 684340999 is about 26159.9120602497. The cubic root of 684340999 is about 881.2332051592.

The spelling of 684340999 in words is "six hundred eighty-four million, three hundred forty thousand, nine hundred ninety-nine".