684840648 has 32 divisors (see below), whose sum is σ = 1812814560. Its totient is φ = 214851840.

The previous prime is 684840647. The next prime is 684840649. The reversal of 684840648 is 846048486.

It is an interprime number because it is at equal distance from previous prime (684840647) and next prime (684840649).

It is a super-3 number, since 3×684840648³ (a number of 27 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 684840597 and 684840606.

It is not an unprimeable number, because it can be changed into a prime (684840647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 838858 + ... + 839673.

It is an arithmetic number, because the mean of its divisors is an integer number (56650455).

Almost surely, 2^684840648 is an apocalyptic number.

684840648 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

684840648 is an abundant number, since it is smaller than the sum of its proper divisors (1127973912).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

684840648 is a wasteful number, since it uses less digits than its factorization.

684840648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678557 (or 1678553 counting only the distinct ones).

The product of its (nonzero) digits is 1179648, while the sum is 48.

The square root of 684840648 is about 26169.4602160610. The cubic root of 684840648 is about 881.4476207674.

It can be divided in two parts, 68 and 4840648, that added together give a triangular number (4840716 = T₃₁₁₁).

The spelling of 684840648 in words is "six hundred eighty-four million, eight hundred forty thousand, six hundred forty-eight".