684469823 has 2 divisors, whose sum is σ = 684469824. Its totient is φ = 684469822.

The previous prime is 684469787. The next prime is 684469847. The reversal of 684469823 is 328964486.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-684469823 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684469523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342234911 + 342234912.

It is an arithmetic number, because the mean of its divisors is an integer number (342234912).

Almost surely, 2^684469823 is an apocalyptic number.

684469823 is a deficient number, since it is larger than the sum of its proper divisors (1).

684469823 is an equidigital number, since it uses as much as digits as its factorization.

684469823 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1990656, while the sum is 50.

The square root of 684469823 is about 26162.3741850773. The cubic root of 684469823 is about 881.2884977029.

It can be divided in two parts, 6844 and 69823, that added together give a palindrome (76667).

The spelling of 684469823 in words is "six hundred eighty-four million, four hundred sixty-nine thousand, eight hundred twenty-three".