684821968 has 20 divisors (see below), whose sum is σ = 1349333280. Its totient is φ = 336606944.

The previous prime is 684821947. The next prime is 684821983. The reversal of 684821968 is 869128486.

It is a super-2 number, since 2×684821968² = 937962255710786048, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 361780 + ... + 363667.

It is an arithmetic number, because the mean of its divisors is an integer number (67466664).

Almost surely, 2^684821968 is an apocalyptic number.

It is an amenable number.

684821968 is a deficient number, since it is larger than the sum of its proper divisors (664511312).

684821968 is a wasteful number, since it uses less digits than its factorization.

684821968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725514 (or 725508 counting only the distinct ones).

The product of its digits is 1327104, while the sum is 52.

The square root of 684821968 is about 26169.1033090551. The cubic root of 684821968 is about 881.4396064499.

The spelling of 684821968 in words is "six hundred eighty-four million, eight hundred twenty-one thousand, nine hundred sixty-eight".