684563639 has 2 divisors, whose sum is σ = 684563640. Its totient is φ = 684563638.

The previous prime is 684563623. The next prime is 684563689. The reversal of 684563639 is 936365486.

It is an a-pointer prime, because the next prime (684563689) can be obtained adding 684563639 to its sum of digits (50).

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 684563639 - 2⁴ = 684563623 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684563609) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342281819 + 342281820.

It is an arithmetic number, because the mean of its divisors is an integer number (342281820).

Almost surely, 2^684563639 is an apocalyptic number.

684563639 is a deficient number, since it is larger than the sum of its proper divisors (1).

684563639 is an equidigital number, since it uses as much as digits as its factorization.

684563639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2799360, while the sum is 50.

The square root of 684563639 is about 26164.1670801881. The cubic root of 684563639 is about 881.3287600986.

The spelling of 684563639 in words is "six hundred eighty-four million, five hundred sixty-three thousand, six hundred thirty-nine".