684332819 has 2 divisors, whose sum is σ = 684332820. Its totient is φ = 684332818.

The previous prime is 684332791. The next prime is 684332821. The reversal of 684332819 is 918233486.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684332819 is a prime.

It is a super-2 number, since 2×684332819² = 936622814320973522, which contains 22 as substring.

Together with 684332821, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 684332819.

It is not a weakly prime, because it can be changed into another prime (684332119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342166409 + 342166410.

It is an arithmetic number, because the mean of its divisors is an integer number (342166410).

Almost surely, 2^684332819 is an apocalyptic number.

684332819 is a deficient number, since it is larger than the sum of its proper divisors (1).

684332819 is an equidigital number, since it uses as much as digits as its factorization.

684332819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 248832, while the sum is 44.

The square root of 684332819 is about 26159.7557136912. The cubic root of 684332819 is about 881.2296939874.

The spelling of 684332819 in words is "six hundred eighty-four million, three hundred thirty-two thousand, eight hundred nineteen".