684959959 has 2 divisors, whose sum is σ = 684959960. Its totient is φ = 684959958.

The previous prime is 684959953. The next prime is 684959963. The reversal of 684959959 is 959959486.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 684959959 - 2⁵ = 684959927 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 684959959.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (684959953) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 342479979 + 342479980.

It is an arithmetic number, because the mean of its divisors is an integer number (342479980).

Almost surely, 2^684959959 is an apocalyptic number.

684959959 is a deficient number, since it is larger than the sum of its proper divisors (1).

684959959 is an equidigital number, since it uses as much as digits as its factorization.

684959959 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31492800, while the sum is 64.

The square root of 684959959 is about 26171.7397014413. The cubic root of 684959959 is about 881.4988055653.

The spelling of 684959959 in words is "six hundred eighty-four million, nine hundred fifty-nine thousand, nine hundred fifty-nine".