684919872 has 336 divisors, whose sum is σ = 2463027840. Its totient is φ = 177168384.

The previous prime is 684919871. The next prime is 684919877. The reversal of 684919872 is 278919486.

684919872 is a `hidden beast` number, since 68 + 491 + 98 + 7 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (336).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (684919871) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3826279 + ... + 3826457.

It is an arithmetic number, because the mean of its divisors is an integer number (7330440).

Almost surely, 2^684919872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 684919872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1231513920).

684919872 is an abundant number, since it is smaller than the sum of its proper divisors (1778107968).

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

684919872 is a wasteful number, since it uses less digits than its factorization.

684919872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290 (or 277 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 54.

The square root of 684919872 is about 26170.9738450826. The cubic root of 684919872 is about 881.4816087780.

The spelling of 684919872 in words is "six hundred eighty-four million, nine hundred nineteen thousand, eight hundred seventy-two".