684012839 has 2 divisors, whose sum is σ = 684012840. Its totient is φ = 684012838.

The previous prime is 684012781. The next prime is 684012851. The reversal of 684012839 is 938210486.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 684012839 - 2²⁴ = 667235623 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 684012796 and 684012805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684012869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342006419 + 342006420.

It is an arithmetic number, because the mean of its divisors is an integer number (342006420).

Almost surely, 2^684012839 is an apocalyptic number.

684012839 is a deficient number, since it is larger than the sum of its proper divisors (1).

684012839 is an equidigital number, since it uses as much as digits as its factorization.

684012839 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 684012839 is about 26153.6391158095. The cubic root of 684012839 is about 881.0923242604.

The spelling of 684012839 in words is "six hundred eighty-four million, twelve thousand, eight hundred thirty-nine".